CHEVY CRUZE P0420 KEEPS COMING BACK! AFTERMARKET CONVERTERS

[Music] hey guys what's up it's eric with advanced love automotive welcome back to the channel some of you guys might recognize this car right behind me it's a 2014 chevrolet cruze it's got the 1.4 liter four-cylinder turbo engine and i did a video with this car a couple weeks ago if you have not watched that video make sure you go back and watch that before you continue i'm gonna leave a link in the description if you did watch that video you'll know that we were dealing with a check engine light and we had several different codes more specifically we were dealing with the po420 which is a catalyst efficiency below threshold and at the end of the video we came to the conclusion that we needed to replace the catalytic converter even though it had already been replaced a few months ago i know a lot of you guys were asking for an update on this vehicle here it is the part just came in so let's go ahead and get started all right guys so over here on top of the toolbox we have the replacement catalytic converter now unfortunately this is an aftermarket unit it is a davaco brand from rock auto we were not able to get the oem one due to budgeting reasons and also the fact that this is a warranty replacement part uh again like i said they recently replaced this a couple months ago so we were able to get this warranty through rock auto so at this point there is no extra cost to the owner of the vehicle which just so happens to be my little brother so we're really hoping that this replacement part is going to last much longer than the first one did now if you guys take a look inside of the catalog converter you can see our honeycomb material or substrate that's in there everything looks nice and clean it is brand new so we are going to compare uh the one that we're gonna pull out to this one we're gonna see if that material is damaged in any way also before we put this on you know we do want to take a quick a moment to do a visual inspection on all of the welds that are on here you guys can see they do a bead weld around here to seal it off you know you want to make sure that you don't have any air leaks or any possible holes you see in this bung hole area right here where the o2 sensor is going to go you can see it looks much cleaner on the outside but it's got this uh weld that goes around it um you know i'm pretty sure they pressure test these or leak test these to make sure that they you know don't have any holes so you know that's what we're hoping is that we get one that doesn't have any kind of manufactured defects again taking a look at the weld here looks pretty clean this weld here looks pretty clean the other weld there looks pretty clean and then finally this one up here it's got some holes in it but it doesn't look like they protrude through the other side you take a look at the inside here nope looks pretty good to me anyways replacing this cat doesn't look too difficult there's essentially a band clamp up here and then three bolts down here at the bottom and there's a couple of brackets here that needs to be removed no big deal we should be able to do this fairly quickly [Music] [Applause] [Music] okay guys so we got the old one out of the vehicle up here on the toolbox and the first thing i wanted to do before i went ahead and installed this is i wanted to do a comparison to make sure that the two catalytic converters were the same again these are both the same brand the same part number but let me show you guys there are some differences so again this is the one that we took off the vehicle and the first thing that you'll notice is that this one had like a heat shield welded onto it now if you look at the one that they sent us as a replacement doesn't have a heat shield at all so i'm not sure really what that's all about the other thing too is if you notice the brackets on here if you take a look you'll notice that they are straight and if you take a look at the bracket on the one we pulled off the vehicle you'll notice that you know these tabs are much wider and they're slotted and if you look at this one right here the bracket has this kind of l-shaped and again the hole is slotted again comparing this to the one that they sent us you can see that you know they're positioned probably in the same way but they are a little bit different so i'm not really sure what that's all about i'm hoping that's not going to create a problem for us now one other thing that i did notice were the flanges here this is again the flange where it meets up to the turbocharger and if you take a look at this flange here and compare it to this flange i mean they look pretty close but when i went to take this gasket and install it i noticed that i really couldn't install this gasket here because it doesn't fit around this center pipe here you guys look closely you know i can get like two of these tabs on but you know i can't get this last one now if you look at it on this one i mean it slides right on there well that's because this pipe here is much thinner than this pipe here now the other thing i wanted to do was take a look at the substrate inside of the catalytic converter we're going to take a close look at what's inside here and see if we can get a visual on the condition of this honeycomb in here you guys see that you can see that this substrate actually looks really really good i don't see any excessive oil buildup it doesn't look dark doesn't have excessive amount of soot actually looks pretty clean i don't see any cracks or any pieces falling out when i shake it it doesn't rattle i mean i'm not really sure what to think take a look at the other side here so this is the side coming right off of the turbo and the exhaust manifold and you can see it looks really really clean now one of the things i was worried about was whether or not this turbo may have been leaking oil into the exhaust you know because that's a possibility if you have a turbo that has a bad seal then it's going to be dumping excessive amount of oil into the exhaust which can cause this substrate in here to deteriorate or clog but as you guys can see this one actually looks pretty clean so to me it really doesn't look like we have an obvious reason for a po420 code other than the fact that maybe the substrate inside of this catalytic converter is not doing what it's supposed to be doing and if you ask me i believe that has a lot to do with the fact that this is a cheap aftermarket catalytic converter again like i said unfortunately we were not able to get the oem one so we're just going to go ahead and put on this replacement part and hope for the best a few moments later now that we got this thing installed let's go ahead and connect the scan tool all right guys so here we have it we're inside the vehicle the engine is idling it's fully warmed up now it's been idling for about 10 minutes or so i just stopped here by the gas station to put some gas in it and as you guys can see the catalytic converter seems to be doing what it's supposed to be doing so if we take a close look at the scan tool you can see the green line is our downstream sensor and this blue line here is our upstream sensor and you can see all of the switching we have happening here the frequency of this upstream o2 sensor but if you look at this downstream o2 sensor we have pretty much a flat line somewhere around 67 millivolts you guys can see it right up here that is the reading that we have right now i'm going to raise the rpm a little bit here you guys can see we have a little bit of movement there i'm gonna let off you see it come back down now what i'm gonna try to do right now is i'm going to snap the throttle you guys see that quick snap we have that quick reaction here where it went really lean and you see the reaction here that's coming up and then now we're back to this flat line here and we're back to switching on this upstream o2 sensor so if you ask me i mean everything looks pretty good so far i think my next task is to go ahead and drive the vehicle and try to complete the monitors because at the moment i did clear the check engine light so we don't have a check engine light illuminated but of course in order to get the state inspection done we're going to need to complete the monitors if you guys recall last time we did this with the old catalytic converter we were not even able to complete the catalyst monitor because before the catalyst monitor could complete it set off that po420 code anyway i'm going to get on the road take this thing for a test drive probably a good 50 miles or so see if these monitors complete and we'll go from there all right guys so one thing that i wanted to show you real quick and this is only because i noticed that the engine started running rough after i filled it up with gas so i'm here at the gas station you guys can see the gas pumps over there so initially after i put gas in it i started it up the engine started running really rough and so of course i had the scan tool with me i figured i may as well check it while i had it and of course we didn't have a check engine light because it had just started happening so there were no code set um and i started going through the data pids and i noticed that the field trim values take a look here we got the long term fuel trim at negative 20 short term fuel trim negative five so at the moment we're running really really rich now from experience what i can tell you with a lot of these vehicles if you have a problem with the engine running rough right after you've just refueled it the first thing you want to do is locate the purge valve because what could be happening is that fuel through the evap system is making its way up and through the intake manifold through this purge valve so if you guys look here this is the hose that goes back to the gas tank or to the charcoal canister this is a purge solenoid right here and then this is the line that goes into the intake manifold so this is intake manifold vacuum gear but what we should never have in this line is actual liquid fuel we should only have fuel vapors coming in right here so real quick check that you can do is go ahead and disconnect this line here what i'm going to do is i'm going to disconnect you real quick and i'm going to put my thumb over the opening in the intake manifold again looking at the scan tool we're still negative you guys can see i mean it's getting a little bit better but we're still at negative 13. uh minus three so somewhere around negative 15 16 20. so again i'm going to disconnect this line here and i'm going to slowly kind of put my finger over it to keep it from stalling again pay attention to these numbers negative 15 negative four so we're about negative 20 on the fuel trim there so again i just open this up i'm going to try to do this slowly oh come on keep it alive keep it alive there we go okay so i got my finger over the hole the engine is still running and take a look at the filter and values there you can see the short term jumped up way positive 23. you can see the long term fuel trim negative nine so right now it is counteracting itself it is trying to zero out the fuel trim values and the engine right now is running much better now that i have my finger over this hole again what we did was eliminated this purge valve right here and so what we can probably assume is that we have actual liquid fuel coming into this line through the evap system we can probably even take a look at the line see if we see any liquid in there let's take a quick look here yeah you guys see how it's wet sorry about the vibration but yeah you can see that we had some liquid fuel coming in through this line here now this doesn't necessarily mean that we have a bad purge valve you know we could also have another problem in the evap system in which the pressure is not venting properly which is what's causing the actual liquid to come up through the evap system that's a possibility again you know we could also have a bad purge valve so at this point i don't even think i'm gonna take this thing for a test drive we're gonna have to try to figure out what's going on with the evap system on this vehicle because we don't want to burn up this new catalytic converter tomorrow all right guys so fast forward it's now been a couple days later and i just want to get you guys caught up on where we're at so far so i went ahead and i replaced the purge valve for the evap system and that did take care of the rich condition that we were having where we had fuel getting up into the evap system uh so i replaced the purge valve i topped off the fuel tank drove it around no longer had any issues with that but i decided to take the car on a test drive to go ahead and try to finish all of the monitors within about 30 to 40 miles of driving the check engine light came back on let me tell you guys i could not believe it when i use the scan tool to look up the trouble codes and there was a po420 catalyst efficiency below threshold anyways after taking the drive the check engine light coming back on i decided to do some more researching googling and trying out technical forums and i found out that i'm not the only one dealing with the po420 on these chevy cruzes so after doing my research i did find some good technical information that i want to share with you guys in case you're dealing with these vehicles with the po420 code and you're kind of in the same boat where you're not really sure where to go next just stick around we're going to go over some points that i came across but right now i do want to show you something really quick we're going to move back inside the vehicle where i've got the scan tool connected all right guys so here we are inside the vehicle i just started it up and let me show you real quick if you look right over here on the instrument panel you can see that we do have the check engine light illuminated like i said we do have a po420 code now what i have here graphed are the oxygen sensors once again we're looking at the upstream the downstream like i said i just started the vehicle up and you can see now that once the vehicle started the oxygen sensors start switching and doing their thing take a closer look here what you'll notice is that during cold startup you know there's some activity here with the downstream o2 sensor that kind of seems like it matches the upstream sensor again this is a cold start i did just start it up so the catalytic converter is not warmed up to the point where it needs to be in order for it to function properly now if you guys recall before when i showed you the graph after replacing the catalytic converter um you know we saw what we were looking for we saw that the front upstream sensor was moving up and down and the downstream sensor was pretty much flat line somewhere up here around 600 millivolts and that's really what we want to see but the reason we were seeing that was because you know i had the car idling for a while the engine had already warmed up and so the catalytic converter was nice and warm it was hot enough to start doing its job you guys pay attention again this is a cold start we've been running for i don't know maybe a minute or two or so and you can see that the catalytic converter still has not heated up enough for it to start functioning properly now we are in closed loop but the oxygen sensors still are kind of matching each other now what i want to do is i want to kind of take the time to see how long it takes for this catalytic converter to warm up and start working like it's supposed to so i'm just going to kind of let this thing run in the background and i'll take note of the time right now so we just pay attention to this graph we can see when this green line here which is our downstream uh starts to kind of flat line the way it's supposed to i guess what i could do while we're at it is i'm going to go ahead and add some other data pins i'm going to go ahead and add the engine coolant temperature data pit and anything else that might be related so let me go ahead and do that real quick okay guys so as you can see i added some data pids up here you can see the engine cooling temperature right about 149 degrees fahrenheit so the engine is still kind of warming up but you can see down here where it says cold startup we're no longer in cold startup mode so whenever we first start this thing up there's a period of time where the engine is warming up and of course during warm-up you know it's going to run a little bit more rich the engine is going to add a little bit more fuel try to get the catalyst up to temperature and try to get the engine up to temperature but right now we're no longer in the cold startup mode and if you look down here we're in closed loop so i'm going to go ahead and scroll down here again we're going to take a look at the graph our two oxygen sensors are still kind of doing uh the thing where they're pretty much kind of matching each other you can see there's really not a lot of time delay between the upstream which is the blue signal here and the downstream which is the green signal here uh they're still pretty much doing the same thing now of course again like i said the catalytic converter is not heated up enough to start doing what it needs to do but i mean we're you know at least five minutes into it look at the clock down here we're at 604 right now you know so we have about five to six minutes worth of runtime and this catalytic converter still is not heated up enough in order for it to start functioning properly okay guys so fast forward a few minutes here and you can see on this graph the oxygen sensors are still kind of doing uh this thing where they're pretty much following each other uh looks like the catalyst has not heated up yet enough for it to start functioning properly and if you ask me i'm pretty sure this is ample time for this catalytic converter to heat up now the other thing that i did notice um and this just started happening now because when i first started this up and it running the first few minutes the field trims did not look like this we were not negative we were actually a little bit positive and now that i'm looking at this it seems to have fallen down and we're down to near negative 20 over here on this field trim i don't know what is going on with this because earlier we were actually positive 10. so these field trims are doing something kind of funky i'm not really sure what's going on here with that that may be a completely separate problem though and i mean i hope it has nothing to do with that purge valve because we did replace it now i will say this the car is idling just fine it doesn't have any uh running issues you can see the needle is nice and steady on the rpm gauge uh but again this catalytic converter is just not warmed up enough um i think what i'm gonna do next is i'm going to try to speed this this process up by uh accelerating the engine so i'm gonna go ahead and raise the engine speed you can see right now we're at around 700 rpm i'm gonna go ahead and raise it to i would say let's say around 2500 rpm and hold it steady and see if we can try to get this thing to warm up and hopefully we can get this catalytic converter to start functioning so let's scroll down here and take a look at this graph again take a look at the engine cooling temperature we're at 176 degrees fahrenheit i'm at around 2600 rpm trying to hold it steady let's take a look at this catalytic converter i guess let's take a look at the field trends while we're at it you can see we're still going negative here even at 500 rpm but uh again these o2 sensors just keep an eye on them and let's see when this thing starts functioning all right so you can see this green line kind of coming up here and you don't see it dipping all the way down to the bottom anymore it's kind of starting to form a straight line here at the top which is really where we want it pay attention you can see how it's slowing down and there we go you guys can see we're pretty much flat lining up here where we want it to be now this cat is nice and hot again let me scroll up here you can see we're at 195 degrees now engine cooling temperature engine speed around 2600 rpm and now our catalytic converter is working so take a look at that so i'm going to go ahead and let off the accelerator let this thing come back down to idle you guys can see the dip in the signal there but then it comes right back up so pay attention to this right now you can see that we're leaned out here but we're still flat lined up here at the top so again here we have a hump right here and a hump right here and a hump right here but you can see that green line just flat line so everything now is working the way it should be this catalytic converter is nice and warm and now it's operating like it was designed to operate again i'm going to scroll up we're going to take a look at the engine coolant temp now we're up to 204 degrees fahrenheit again we're at idle here and you can see that we're still in closed loop but again scrolling down here now our catalytic converter is working the way it should be check that out but what i still don't like is the fact that uh looking down here we're still at negative 20 on the long term field trim there which earlier like i said it was not negative we were actually positive like 10 or 15 and so there's something else going on here i'm gonna have to double check that purge valve and see if that's not giving us an issue at the moment but the point i'm trying to make here is the catalytic converter again it was taking way too long to heat up by itself in order for it to start functioning we actually had to raise and hold the rpm to try to raise up the engine temperature and raise the temperature of the catalytic converter in order for it to start functioning like it should now is that normal i don't think so i'm pretty sure on a normal vehicle or a good operating vehicle it should not take this long for the catalytic converter to heat up but in this case there's something happening here all right guys so i'm back under the hood and as you can see over here i'm retrying this test where i disconnected this evap line from the intake manifold and i've got my finger covering the hole here and take a look at the fuel trims almost immediately they corrected themselves so you can see our long term here negative one our short term here positive one kind of jumping around but it's staying near zero so pretty much immediately after i disconnected this line and put my finger over the hole we corrected the problem so we still definitely have a problem with this evap system even though i replaced this purge valve seems to me like we're getting fuel up inside of this line here and that can really only mean one thing is that we're probably going to end up having to replace the evap canister because at this point it only makes sense that more than likely the evap canister is filled with liquid fuel okay guys so moving back over to the issue with the catalytic converter again as i showed you on the scan tool we could see that the catalytic converter was taking way too long for it to reach operating temperature as you guys can see we had the engine idling for around 10 minutes before we decided to go ahead and raise the rpm in order to force the catalytic converter to heat up so that it can start operating properly now the reason i showed you that is because while i was doing some research i ran across an article on iatn if you guys don't know what iatn is it's a forum it's an online network for technicians it is a paid form but there's a lot of information in there for technicians especially guys who do this for a living if you don't know about iatn look it up join the network promise you there's a lot of information in there that really can help you figure out what's going on with your vehicle anyway so i ran across an article where somebody essentially was running into the same problem they replaced the catalytic converter replaced the upstream downstream oxygen sensors and they could not get this po420 code to go away and a technician or an engineer chimed in on the forum and he mentioned something that i thought was really interesting so what he said was that after 2010 the manufacturer changed the way the catalytic converter is monitoring the catalyst see before 2010 when the computer was monitoring the catalyst it was doing it while you were driving at highway speeds so what we would do when we tried to complete a catalyst monitoring was to get up on the freeway or on the highway hit 50 55 miles an hour and try to keep that speed steady on the highway for at least five minutes or so because that's really when the computer is monitoring the catalytic converter and that's how you're gonna get the monitor to complete well according to this guy on the forum what he's saying is that after 2010 the computer is no longer doing it that way the computer's actually monitoring the catalyst during startup which i thought was really interesting because if that's the case this really does not give us a whole lot of margin of error for our catalytic converter to pass the catalyst monitoring test and by the way he wasn't the only one that mentioned that somebody else said the same thing and i thought well if two technicians are saying that maybe there's really some truth behind it so i went back over to all data and i looked up the po420 code description for this vehicle in particular let me show you guys what i found all right guys so over here on the toolbox i have the dtc description printed up and as you guys can see right here at the top dtcpo420 catalyst system low efficiency and of course it gives you a system description which you know i hope you guys are already familiar with it just tells us that the three-way catalyst converter works to reduce emissions and it also goes on to tell you how the ecm determines the catalyst efficiency i mean if you read it here it says the catalytic converter also stores oxygen the ecm monitors this process by using a heated oxygen sensor that is in the exhaust stream after the three-way catalyst converter the downstream oxygen sensor produces an output signal that the ecm uses to calculate the oxygen storage capacity of the catalyst this indicates the ability of the catalyst to convert the exhaust emissions efficiently the ecm monitors the efficiency of the catalyst by allowing the catalyst to heat then wait for a stabilization period while the engine is idling the ecm then adds and removes fuel while monitoring the downstream oxygen sensor when the catalyst is functioning properly the downstream oxygen sensor response to the extra fuel is slow compared to the response of the upstream sensor which is located before the three-way catalytic converter when the downstream oxygen sensor response is near that of the upstream oxygen sensor the oxygen storage capacity or capability and efficiency of the catalyst may be degraded below an acceptable threshold so again essentially what it's saying is that the upstream signal is going to move fast and rapidly up and down while the downstream sensor is going to move across very slowly that's how the computer determines whether or not the catalytic converter is doing what it's supposed to do now that's information that we already know or at least you should know if you've already reached this point in the video but what's really important that i want to show you guys here are the conditions for running the dtc now this is really important because this is going to tell us when the computer is monitoring the catalytic converter for catalyst efficiency so again if you guys read over here it says before the ecm performs the idle test again keyword here is idle test so this test is being done during idle the vehicle must be driven under the following conditions first of all the engine speed must be greater than 1100 rpm for a minimum of five seconds now what this is referring to here is our cold startup so if you guys know whenever you first start up a vehicle you're going to have a fast idle in which the idle rpm is going to be usually above 1100 rpm for a certain amount of time to try to get the engine warmed up so that's going to be the first condition and the next one here it says here that the vehicle speed is less than one mile per hour so this essentially means that the vehicle needs to be sitting still it cannot be cruising down the road next it tells us here that the engine run time is greater than 120 seconds so again our fast idle here um you know we're going to have 1100 rpm or above during our fast idle and it's going to be more than five seconds usually our fast idle lasts at least about a minute or so so again we're going to have the fast idle the vehicle is not moving and of course the engine run time has to be longer than 120 seconds which essentially is going to be what the fast idle is so now once our fast idle comes down let's take a look at the other parameters it's looking at so again the run crank voltage has to be greater than 11 volts of course when an engine is running and idling usually our charging system is sitting somewhere between 13 to 14 volts next up it's looking at the intake air temperature which i mean it gives you quite a range here you know it could be extremely freezing outside or it can be really hot so it doesn't matter as long as the iat is operating uh next up is going to be looking at the engine coolant temperature sensor again it gives us a range here of 104 degrees to 284 degrees fahrenheit so it's got to be within this operating range here the next thing it says here is that the engine has been idling for less than 50 seconds now this here is kind of key because if you guys remember up here it tells us that we have to have a fast idle of at least five seconds and our engine run time has to be greater than 120 seconds but our engine idle time has to be less than 50 seconds so essentially this is happening during cold startup that means our catalytic converter has to warm up pretty quickly and get into operating range by the time this monitor kicks in and starts watching that waveform so again if you look here the next one it says the field trims between negative 20 and positive 30 which is pretty much the entire range we go to the next page here follow it up here at the top you'll see barometric pressure reading mass airflow sensor it gives us a range here tells us that the engine has to be in closed loop and the catalyst here which is really important because this is the actual temperature of the catalytic converter has to be at least between a thousand and 1700 degrees fahrenheit so that means that this catalytic converter has to heat up really really fast and the next thing here says that the uh automatic transmission has to be in drive range uh so that's interesting if it means or if it's saying that the transmission has to be in drive i'm not 100 sure about that but again this is what the manufacturer wrote out so this is what i'm following uh but this last point here that it makes is really important so it says here that this diagnostic attempts one test during each valid idle period once the above conditions have been met this diagnostic attempts up to eight tests during each drive cycle so that's pretty much everything that the computer is looking for in order for it to try to determine whether or not the catalytic converter is going to pass so you guys can see that we don't have much margin for error when it comes to trying to use a cheaper or inferior replacement part for the catalytic converter a lot of times these after-market replacement catalytic converters just won't cut it they aren't using enough of the precious metals inside of the catalyst material or the substrate in order for it to convert the gases the way the original equipment would the other problem that i'm noticing here is that it's taking way longer for this aftermarket catalytic converter to heat up and as you guys can see in this case with this vehicle that's just not going to cut it so over here on the toolbox i have two catalytic converters side by side if you look over here on the right side this is the original equipment catalytic converter that came off of a vehicle and if you look over here to the left this is the aftermarket replacement that my brother put in there now the first thing you'll notice these two side by side is just the sheer difference in size i mean look at the girth of this catalytic converter compared to this one over here i mean it's almost comical and if you take a look inside again the substrate that's in here now this catalytic converter is kind of dirty because it's been sitting out we got some rust inside but i mean look at the size of the substrate the honeycomb that's in there i mean it is massive take a look inside of there and you can see that it fills up this entire shell and if you look at this aftermarket catalytic converter again we take a look inside you can see that tiny little substrate that they put in there i mean that's pathetic so not only is this thing inferior in size it's also inferior in the amount of precious metals that they actually put in here in order to do the job properly i mean hindsight is 20 20 but if you guys ask me now if you were to look at these two side by side i mean you could tell obviously this one cannot do what this one can do from the factory there's just no way so right now the plan of attack is we're going to go ahead and remove the aftermarket catalytic converter that's in the vehicle right now again this is the first one that my brother replaced we ordered a second one to put into the vehicle as a warranty replacement for this one but again the one that's in the vehicle is doing the same thing that this aftermarket one is doing and with the knowledge and information that we have now we know that it's better to go with an oem catalytic converter now like i said these converters are not cheap so what we're going to try to do is we're going to send these two aftermarket catalytic converters back we're going to try to get the money back for those and use that money toward buying an oem catalytic converter so in the meantime what i'm going to do is i'm going to put this one back onto the vehicle let them drive it with that while we wait for the refund on these two i am planning on making another video on fixing the issue with the car running rich slash running lean whatever the issue is that's going on there we want to fix that before we replace the catalytic converter especially if we're going to put the money in to buy an oem one so keep an eye out for that video like i always say guys thank you for watching i hope you found it useful i hope you find it informational if you did make sure to give it a thumbs up if you haven't done so already make sure you subscribe to the channel hit that notification bell and i'll see you guys in the next one thanks [Music] [Music]

Channel: ADVANCED LEVEL AUTO

Views: 20,035

Rating: 4.8868613 out of 5

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Id: FPuURVDLNNc

Length: 33min 18sec (1998 seconds)

Published: Fri Feb 26 2021