Every engine part changed, still has P0171 P0174 codes Pt1

[Music] foreign hey Merry Christmas and happy New Year at the time of this filming so hope you got something really cool for Christmas I think I did here yeah that works just fine all right I think we've got a good one for you today let me grab some notes uh this vehicle right here is a 1998 Ford F-150 it has a says a Triton V8 on it I think I've seen some of these before but not not as early as a 98 and it has a lean problem that has everybody stumped so let's get a history here get a lot of notes on this one so this owner actually found me on the Nextdoor app again and uh what we've got here um so the car started running bad the uh owner did a code scanner on it found uh po171 PO174 Bank One Bank two lean conditions gosh we've got a thousand videos of that on this channel uh the owner changed let's see here plugs wires O2 sensors both coils both both coils I'm not quite sure what that means exactly both coils I don't know um mass airflow sensor DPFE sensor EGR valve throttle position sensor and the fuel pressure regulator so Parts Cannon got fired pretty heavy on this at that point he gave up and took it to a shop which uh that's it's kind of funny this is off the topic a bit but not that I'm talking about this guy but I see this a lot in comments where people fire the parts came in at their car and they put like two thousand dollars into it and then I'm like well you know take it to a shop that can diagnose it they're like no way those guys don't know what they're doing I don't trust them on my car okay because you're doing so much better um anyway I think this guy's a bit of a do-it-yourselfer and um you know like I am but probably probably a little bit less diagnostic minded I guess he finally gave up figuring that it would be cheaper to just take it to a shop and get it fixed so then the shop comes in now this shop um I have actually done some stuff for them before they have actually sent me occasionally maybe two or three times some cars when they uh had some issues and they just know me from the channel and so let's see the shop um oh yeah that's right okay so the shop did uh they they can talk a little bit higher level here so the shop looked at the fuel trims they found the fuel trims were maxed at about 60 total trims so I'm assuming that's 30 on the short 30 on the long I guess that's that's Max on this vehicle I suppose uh let's see found that the vehicle had a terrible drivability problem and the guy had mentioned that too that the vehicle definitely drove very poorly they did a fuel pressure test they found that the fuel pressure was only about 25 I'm not quite sure what spec on the car is I think on these Fords it's a little bit lower than you're used to on a GM with like a 55 60. I think it's if I remember correctly probably more around 45.50 so 25 would be pretty low they replace the fuel pump and then they test drove the vehicle and they found that the vehicle drivability problem was solved so uh much improvement after the fuel pump but they found that the fuel trims hang on a fuel trims would not adjust the long-term below 30. so uh we're still high on the long-term fuel trim they said short-term trims were zeroed and uh so they drove it got check engine light they even had Freeze Frame where it showed that it had check engine lighted 1800 RPM with what like 23 instead of 23 or 28 28 maybe throttle so probably not a vacuum leak where are they at here uh with the fuel pump they replace filter they said um they checked for vacuum leaks and none were found although I did talk with them and they of course didn't expect a vacuum leak given that data neither would I they uh measured compression found that it was good they um again checked for vacuum leak thinking because they said there was some inconsistency where there were other times where it seems the fuel trim did improve under load um they on a guess replaced the intake manifold gaskets and they they admit that they just thought there was maybe vacuum leak that they couldn't find with their smoke tester or however they were doing it I'm not sure how they did it maybe they were using carb cleaner and they just felt like they couldn't find the location replaced intake manifold gaskets fuel trims improved to 25 total trim so that's still that's still at the threshold the check engine light for it to come on they um again checked uh compression they checked EGR they checked all of the owner's previous work they reset the cam the cam Kam that would be um what's Kam keep a live memory I believe reset the cam and then upon starting the car found that the short-term trims immediately jumped to 25 on both Banks they knew they had an issue they didn't feel comfortable returning the card of the customer knowing the check engine light would come back on they offered to do a fuel injection cleaning but they didn't think that it would really help and they wouldn't guarantee it at that point the owner found me um I got in contact with the shop and the shop agreed to bring me the car so that's where we're at with this um they did tell me uh they reset the cam and the fuel trims haven't gone as high as before they um said when they drove the car over so they drove the car over the two guys and this part I remember because I talked to him so they had uh two guys come over one following behind in the truck the guy said when he drove the truck over it drove absolutely perfectly fine so the check engine light didn't come on but he was looking with the scan tool and the fuel trims were definitely going fairly high as high as 35 or 40 total trim uh he said that the problem is is that it's it's not really stabilized because they had only reset the cam not long before so he recommends I drive the truck around a little bit and get a better feel for it the only trouble is we've got a massive snowstorm right now there's like eight inches of snow and one of the things that of course I would want to do is do a wide open throttle test and kind of look at the e02 sensor response on wide open throttle there's no way I can do that right now so um we're just gonna look at the truck as it is so that's that's all I know right now we got a lot of background data and we've certainly got a lot of parts replaced in the car too so um we I think the easiest thing to do is let's check where the fuel trims are at keep in mind that they're probably still kind of stabilizing a little bit and we'll just go from there this is a big truck let's get this positioned up here all right I um remember seeing I think one or two of these before I remember this air filter is like whoever designed this needs to be shot I remember replacing an air filter I think and um and and lining this up was like like so frustrating uh there's MAF sensor in here um not quite sure how you access that quite yet let's see there's a there's a connector right here it looks like he pried this connector off of a off of a bracket or something to replace it uh we got a brand new fuel pressure regulator there um new spark plug wires it looks like what I'm trying to do I'm kind of confused on the two coils both coils so we got wires on here oh okay I get it I get it um I don't know if it's a view in the camera but it doesn't matter we've got uh two ignition coil packs and each of them one for each bank and each ignition coil pack is for four cylinders so we've got two coil packs so those were replaced okay now I get it um yeah so let's uh get some data off of this thing and take a look at some fuel trims all right you got to keep in mind is it do it yourself or you just don't see like a whole ton of cars I see more nowadays you know since more people have kind of found my channel and stuff but uh when you're working on a unfamiliar system it it's often a little more challenging uh one example is I asked the shop if they um check the map sensor and I didn't realize apparently there is no map sensor on this vehicle I didn't know that so uh one less thing to worry about maybe yeah it starts right up no check engine light sounds good yeah that sounds really good yeah there's no check engine light on right now curious to see what these fuel trims will be let's go take a look yeah let's just gonna start off with the enhanced here usually I like to start off with the generic just to prevent any communication problem but on a 98 I'm not really quite as concerned about that all right I'll come back after this loads all right okay checking for codes here and we only have yeah we got no pending codes or anything um this would be second well it's not really a drive cycle but at least second one p1000 I believe is from the cam clear um and also they may have cleared the cam by possibly just disconnecting the battery and rounding out the um the ground in positive possibly not quite sure how they did it let me just I want to take a look at what kind of bi-directional controls I have here evap just idle control okay so um not a whole lot of bi-directional controls which I'm not surprised about let's just start off well long term is a little bit High there uh long term two I mean that's not horrible really depends what the short terms are now short-term zeroed okay um and there's a little bit of difference between the banks too but we do have a pretty high total trim going on on both Banks so actually when you look at total trim where we're hovering around 20 which which is definitely High they said they would see it as high as 30 when driving let me increase the throttle a little bit get this off here it absolutely sounds great seems like it would drive good oh new EGR valve looks like um all right yeah let's look at the effect on fuel trims when I give it some throttle all right in just that time it looks like we did get some adjustment up higher so yeah we're over 20 total trim on one and uh it's climbing it looks like that's going to definitely set a code looks like we're higher than that on Bank two for a little bit it is um it is awful jumpy but it's definitely trending upward so I agree with them that that this is a concern because over time this does seem to be getting worse all right let's see what happens with throttle okay that's a little confusing so what's happening because I believe What's Happening Here we have the fuel cell memory cleared from the cam reset so it looks like we improved dramatically on the long term but I believe it's because those fuel cells haven't been assigned yet if you noticed it did look like the short term did increase pretty dramatically even though we were zeroed on the long term so I I agree this doesn't look like a vacuum leak this just looks like a um the effect of the cam reset so we need to calculate this so so I need that short term to stabilize so we're wow it goes between five and ten so we're between 20 and 25 total about 23 total there so yeah we're right on the threshold for setting a check engine light so 25 and 23. let me do that again okay without question total trim is improved but not not totally no pun intended there um I want to graph this out okay why did only three of them show I need to add one long term long two I need short-term Bank two here there we go now let's see I want to uh We're not gonna go negative I don't believe so let me adjust these scales so I can get a little bit better resolution on the amplitude here okay so again this this is a little confusing here but we have to keep um our negatives here are are not for our short-term trims we've got green and orange so we're running just about a zero um yeah right around zero to a little bit slightly negative on bank one trim using this scale and uh Bank two is green over here so our fuel Trims on the short term are zeroed long terms definitely are high and the other thing I hate I don't like the auto scaling I want these scales to be congruent so let me adjust that okay there we go so now we've got our scales matched up so yeah we've got just a little bit higher trim on Bank One um what's funny now is we're adjusting negative all of a sudden like really adjusting negative so that brings our total trims down about 15. now let's Supply some throttle okay it it definitely definitely definitely this is funny that looks like vacuum leak that screams vacuum leak all day long but the problem is again that's keep alive memory thing that would set much higher there's no question it's worse under load do not suspect vacuum leak here um dirty mass airflow or fuel pressure now here's the problem with that um mass airflow sensor was replaced and the shop replaced the fuel pump and said that it drove much better as a result one of the things I guess is possible um I guess it's possible if the shop replaced the fuel pump but they didn't clean out the tank what if there was a whole bunch of sediment in the tank we've seen this before although it it usually would take more than a day for it to uh contaminate the new pump but maybe the new pumps contaminated um I'm kind of thinking fuel pressure may be a good way to go let's try that one more time yeah there's no question those trims would pull up so mass airflow or fuel pressure mass airflow sensor was replaced um dirty mass airflow Maybe the guy you know the do-it-yourselfer guy replaced the mass airflow sensor so maybe there's some variable there mass airflow sensor should be easier to check plus I kind of need to figure it out um let's do this let's get a mass airflow reading on this maybe that'll help all right let's go down here let's see what other data we have we need to collect more data um okay well I know my O2 sensors are working oh did he replaced O2 sensors didn't he let me check my notes yeah O2 sensors were replaced and I'm not worried about O2 sensors because we can see the the short term so I know those are working uh barometric pressure well that's interesting it's just I I thought this did how does it know the barometric pressure without a map not quite sure um the hurts is flagging High I'm not quite sure what a specification would be on that I saw another kind of map sensor-like thing somewhere here um there it is barometric pressure PSI 14 point okay so that's probably just a tiny bit low remember I am in Colorado um so so I'm not expecting um the other thing if this was reading high if we think about it think logically about this if this was high we would have a rich condition um because if we're expecting a higher barometric pressure than what I'm at you're going to get fuel compensation for that accordingly it's going to um it's going to create a rich condition so I don't not too worried about these right now short term has pulled down our long term here I see but but it definitely is is a problem under load all right let's get some more data here uh let's see uh engine load should be around uh 12 let's see what happens when we increase looks about right wow that that short term definitely it does not like being under load and that's a big clue for sure all right uh DPFE here we may look at that um now we've got a diagnosis and understanding of DPFE on my paid Channel that explains not only the DPFE on Fords but how to use them in Diagnostics uh that may come into play at a point okay I don't think we've got like an exhaust back pressure issue or anything like that we may come to that from a diagnostic perspective later uh let's see here I'm gonna put engine RPM up here for you guys just so you can kind of track better as I'm increasing throttle and stuff anything else good here uh evap definitely not worried about evap problem here uh let's see EGR so EGR was replaced now let's see a blockage of the EGR no no I'm not I'm gonna just rule out this real quick put this on the EGR valve here now EGR valve absolutely works there's no clog or anything there uh let's see fuel injectors all right maybe uh we'll come back to that later possibly a fuel issue totally agree fuel pump Duty I would expect that to be a hundred I don't think this has like a pulse width modulated fuel pump I I can't imagine it does on a 98 I don't know fuel rail pressure transducer oh man can I get fuel rail pressure that would be amazing no I can't I can't get fuel rail pressure that would be awesome I would love that uh this is not an idle air control problem this is not going to be a IAT problem just want to see if it actually works yeah it's about right um intake manifold tuning valve does this have an intake manifold tuning valve all right put that on the checklist there it is mass airflow I want that um okay and again I hate this I I hate the pounds per minute because it gives you kind of a gross calculation I like grams per second and I don't think I have that available I could calculate it but the trouble is is that you've got kind of a rough calculation there uh to begin with so you've got a lot of margin of error when you um extrapolate it out uh let's get um so barometric pressure that's this is not a map Reading that's the actual barometric pressure that it reads when it uh resets it wide open throttle so that's not going to vary that's what it is what I want is mass airflow sensor voltage there it is mass airflow sensor voltage so does this have a rev limiter on it it has a rev limiter so that screws this up what I kind of like to see is to get kind of close to four volts on a wide open throttle this rev limiter is going to kind of screw me up though let's see how high I can get it though all right 3.4 um well it's not the four volts or so that I would like to see but that's pretty I mean it's pretty responsive you can see the map sensor responds accordingly as as well I would expect it to if the guy replaced it um I'm kind of putting that after fuel pressure right now that rev limiter though kind of kills me because I can't really get it to the wide open throttle it'd be easier if I can drive the car and do this but I can't with in a in a massive snowstorm especially a wide open throttle right plus the tires on this car are completely shot um we're gonna put this on the back burner here with the math I'm really thinking fuel pressure right now where is our map okay so let's see misfire there's definitely no misfires let's just pull that up yeah there's definitely no misfires the car actually seems to run amazing O2 sensors I'm not worried about you can um why did it go to throttle position mode I want my short term back up there short-term one now are these going to go positive here okay we may check just to make sure that the oxygen sensor well if the oxygen sensors weren't responding we wouldn't hover this close and there's a zero there I all right oxygen sensors are working not going to waste my time um what else do we got here okay that's a good one rear OT sensors uh would be good to look at them and expect those to stay Rich of course all the time oh there's a secondary air is there a secondary air injection oh that that could cause a lean condition but not under load that would be some leak in that system are out now that's that's going to be very very very unlikely that secondary air is causing that uh TPS input not worried about obviously any kind of timing or compression possibilities here and that excludes everything let's um pull up some reroutes whose oh boy there's a lot of stuff here okay so we need uh Bank One Downstream voltage and I'm gonna say this guy is oh wait that's Upstream I was gonna say that guy's catalytic converters toast um where's Bank One Downstream Bank One must be this yeah that's good okay good and I'm not really worried about Thing Two and I did see some positive on here okay so we've got OT sensors I am eliminating the O2 sensors work fuel pressure is where I want to go

Channel: Schrodingers Box

Views: 62,384

Keywords: o2 sensor bank 1 lean, o2 sensor bank 2 lean, P0171, P0174, P0172, P0173, scannerdanner fuel trims, south main auto P0171, South Main Auto P0174, fuel system lean, engine diagnostics, P0340, check engine light

Id: Au49Z1SM8Hg

Length: 28min 10sec (1690 seconds)

Published: Fri Dec 30 2022