Trouble with P0171/P0174, and now P0460??

Hi all. Long time lurker and learned soooo much from you guys so thank you!!

Today I need some advice with these codes I've been getting.

Background: I have a (May) 2004 330i. I pulled the intake to locate a leak and fixed it (oil filter housing gasket). I also replaced the manifold and throttle body gasket along with replacing broken or brittle vacuum pipes since it was apart. This was about a year ago. Since putting it back together I have gotten P0171 (System too Lean (Bank 1)) and P0174 (System too Lean (Bank 2)) codes intermittently. Seemed to happen more when it was cold but not always, however that was the only pattern I could discern. The codes started with reading as two of each then went to two of P0171 and one P0174. I figured it was air in the line since I popped the fuel line off when doing all that work, but then more recently was thinking it was the fuel filter and need to get to it (48k miles now).

Yesterday I got the three codes again, though this time when I read the codes I also had a P0460 (Fuel Level Sensor Circuit Malfunction).

Initial searching brought me to TKC's thread where he replaced the sender, pump, and filter. http://forum.e46fanatics.com/showthread.php?t=592414

I haven't had a chance to pull it apart again to make sure the elbows were tight and no new holes (I had to get a new elbow off the TB because I butchered the old one to get it off) as I've found that and bad precat O2 sensors can cause the 171/174 codes. But now with this new code I'm getting a little worried. I need this car for work (unfortunately I do some field service in it) so pulling it apart has been backseated. It can be sluggish at times but it usually only lasts a second or two. And the SES comes one usually after driving and I'm stopped at a light.

Does this sound like I need to replace the sender, pump, and filter? Could the codes be coming from something I did in the engine?

I have INPA on my laptop and can see misc levels from the engine and I noticed the precat O2 sensors were only at 49%-50% while the postcats were 100%. This was with the engine temp at normal/middle of the gauge.

I'm unfortunately on a budget and at times have limited time to work on it so any help, suggestions, advice, BS to narrow it down is so gratefully appreciated!

Also if I'm not in the right forum I'm truly sorry. I wasn't sure if this was the right one or the DIYor even the Tuning and Tech/Driveline was the right place.

thanks!

What are the Mv reading for all four o2 sensors?

check the DISA intake for leaks!! Use combustion chmaber cleaner and spray around DISA inlet to manifold.... check for changes to engine RPM... had same issue (except for last code), and problem was with DISA seal and flap inside DISA broken. Flap repaired and DISA reinstalled and no issues since.

I wouldn't replace the fuel level sensor and sending unit yet. First just change the fuel filter first and see if that does it. I think if the filter is clogged you get some of the same symptoms as when the sending unit isn't working right.
As for the 0174 and 0171 codes, as the poster above stated it could be a small leak in an intake hose. Easy to rule out with some brake cleaner before you go changing the O2 sensors out.

Look into intake tears, MAF sensor clean or replace and DISA as stated above.

I had the same codes and it was the MAF sensor. I also replaced the fuel filter and DISA as i had 95k miles. I replaced them as preventative.

Like grandsrus, same codes and MAF sensor. If they keep coming up you need to replace the sensor. Make sure you take care of it quick, you're not doing your engine any favors by running lean.

@kamagazi: In INPA the precats are at 1.5v and the postcats are .67v - .70v. Though when I was looking at them they actually dipped a little bit. The Bank1 postcat sensor dropped to .11v but then went back up to .67v. If they were constant that would be the sensor, right? This means more the fuel is not getting there? The percentage I noticed before are the 'lambda sensor heating' readings. Both precats are 46% and postcats are 99%. I also checked the error memory and it was listing "2882 mixture preparation bank1", saying "signal or value above threshold" and giving the P-code P0171. In the 'detailed' list it shows "average value bank1 5.86%" but unsure which value that really is in INPA.

@everyone: I sprayed some CRC brake cleaner around the DISA and the elbows but no change in RPM. I only did a quick spray of it in those areas but could def smell it so not sure if I it was enough to find an intake leak. I sprayed some at the front air intake but it didn't seem to change any so I might not be spraying enough. As far as the MAF, I don't have MAF cleaner but looking at it it is very shiny so could it still be dirty even if it looks clean and shiny? I know oil from the K&N filter can mess with it but it's looking clean. And could I use TB cleaner and be safe? I know they make MAF cleaner for a reason but in ATL it's snowing and gonna be a PITA to get any probably for the next 24hrs.

damn... did a search on that 2882 code and found this thread over at bimmerfest. My separator was replaced before I bought the car (it looks new and was told it was replaced) but maybe this is it or I have a leak somewhere in those lines? I tried opening the cap while running and there's a small vacuum and the idle does change a little bit when the cap is put on and taken off, is that normal? There's also a little 'sucking' sound from around the separator so maybe I didn't plug something in, again? Pulling this intake again is gonna ssuuuck lol

again, thank you everyone! this is really helping me get to the bottom of this!

addition: btw, should the DISA make noises like in this video? I don't think mine are as loud but sound similar.

Originally Posted by ABOC

Like grandsrus, same codes and MAF sensor. If they keep coming up you need to replace the sensor. Make sure you take care of it quick, you're not doing your engine any favors by running lean.

no, thats not always the case. Quite a few other things that it can be.

a small side question to all of this... been reading more as I gave up tearing out the intake for the night. What is 'multiplier adaption' and what would be decent values? Some of the screens i printed shows a multiplier of like 12%, but the additive is like around -1.0 to 1.0. It seems to deal with mixture trim but with taht i'm kinda lost.

thanks

add: btw, i'm pulling the intake to make sure the stupid CCV is ok, along with its pipes, and to maybe replace this leaking oil line (not too bad just on the line tho).

Originally Posted by envoid

addition: btw, should the DISA make noises like in this video? I don't think mine are as loud but sound similar.

__________________

Follow my cross country drive to Bimmerfest West 2013
http://forum.e46fanatics.com/showthread.php?t=987217


Youtube - Electric Fan Swap/Aux Fan Removal - Projector Retrofit - E46 Bulb Guide

Solidjake

View Public Profile

Find more threads by Solidjake

Find More Posts by Solidjake

Leave feedback for Solidjake (16)

Originally Posted by Solidjake

No it shouldn't. That is my video and I replaced the DISA with a new one.

Man, thank you! I wasn't sure if you were active on here. I was starting to lean to it last night but it is now on the list to replace. Now trying to find time to get the CCV out. At least found the PN for the oil line. Working sucks.

Originally Posted by envoid

Man, thank you! I wasn't sure if you were active on here. I was starting to lean to it last night but it is now on the list to replace. Now trying to find time to get the CCV out. At least found the PN for the oil line. Working sucks.

LMAO, I post a lot everyday.

I need to do my CVV as well.

Originally Posted by envoid

Hi all. Long time lurker and learned soooo much from you guys so thank you!!

Today I need some advice with these codes I've been getting.

Background: I have a (May) 2004 330i. I pulled the intake to locate a leak and fixed it (oil filter housing gasket). I also replaced the manifold and throttle body gasket along with replacing broken or brittle vacuum pipes since it was apart. This was about a year ago. Since putting it back together I have gotten P0171 (System too Lean (Bank 1)) and P0174 (System too Lean (Bank 2)) codes intermittently. Seemed to happen more when it was cold but not always, however that was the only pattern I could discern. The codes started with reading as two of each then went to two of P0171 and one P0174. I figured it was air in the line since I popped the fuel line off when doing all that work, but then more recently was thinking it was the fuel filter and need to get to it (48k miles now).

Yesterday I got the three codes again, though this time when I read the codes I also had a P0460 (Fuel Level Sensor Circuit Malfunction).

Initial searching brought me to TKC's thread where he replaced the sender, pump, and filter. http://forum.e46fanatics.com/showthread.php?t=592414

I haven't had a chance to pull it apart again to make sure the elbows were tight and no new holes (I had to get a new elbow off the TB because I butchered the old one to get it off) as I've found that and bad precat O2 sensors can cause the 171/174 codes. But now with this new code I'm getting a little worried. I need this car for work (unfortunately I do some field service in it) so pulling it apart has been backseated. It can be sluggish at times but it usually only lasts a second or two. And the SES comes one usually after driving and I'm stopped at a light.

Does this sound like I need to replace the sender, pump, and filter? Could the codes be coming from something I did in the engine?

I have INPA on my laptop and can see misc levels from the engine and I noticed the precat O2 sensors were only at 49%-50% while the postcats were 100%. This was with the engine temp at normal/middle of the gauge.

I'm unfortunately on a budget and at times have limited time to work on it so any help, suggestions, advice, BS to narrow it down is so gratefully appreciated!

Also if I'm not in the right forum I'm truly sorry. I wasn't sure if this was the right one or the DIYor even the Tuning and Tech/Driveline was the right place.

thanks!

I have been getting the same 2 codes 171/174 and cannot narrow down the cause, i have checked for vaccum leaks and eveything is good! However mine is always affected by weather, when it gets below 30 for a period of time, ill get the check engine light, as soon as its above thirty no code at all, the car seems to run better when the weather is warmer. I know i "run" better when the weather is warmer!!

I do get the rough idel when im at a stop light or stop sign, no stalling. the car runs great! Still has great power... This has been driving me nuts, so i know how your feeling!!!

Originally Posted by Solidjake

LMAO, I post a lot everyday.

I need to do my CVV as well.

wow, i'm flaking then.

But I did have a question for you tho... When you pulled the DISA was the flap broken or was that pressure manifold thing on it the cause? Mine seems intact and that pressure thingy seems ok as it blows air out and sucks air in with no leaks from the vent port (stuck finger on it) so wanted to see if you knew what was wrong with yours in case something else I'm not looking at is killing it.

@cdrshm: I just got my CCV out without taking the intake manifold out and it's a PITA! Kinda rather take out the intake than do this again. Anyway, one pipe was brittle (the one that snakes through the intake manifold and pops out the top of it and #3 in this pic) and might actually be what was causing the oil leak I found on that oil line. I couldn't see anything before breaking it out but where it broke makes sense with the oil on that line as it was right above it. But, best way to tell if the pipes are ok is to pull the intake, even though it is a huge PITA. I had to do it twice before but when it's out you can see everything with the CCV, intake, and the oil filter manifold/house/casing/thing that attaches to the engine. When I tried brake cleaner to find the vacuum leak it didn't do anything, and with the colder weather makes me think either a small crack that opens up when cold or a gasket that is shrinking when cold. But it's probably a crack in a pipe. Though when I tested mine it was warm.

One thing I noticed with these CCV pipes is that it seems they go brittle from the heat they endure rather than the mileage on them but that is only my observation... My car was originally in Miami (looks like it got in a small front-ender) and made it's way up here after being fixed. Anyway, the car only had about 33k miles but those pipes were horrid, along with the leather being dried out. This one pipe that I broke wasn't one I replaced back almost 2yrs ago so I guess it's time for it now lol.

One question for everyone: Is it worth getting cold-climate parts for Atlanta? It can get damn cold here but almost never less than the teens.

ok... I've concluded the DISA and CCV are ok but there might be an air leak between the DISA and intake manifold along with that pipe that was becoming brittle. Might be getting the pipe tomorrow from the dealer (only $2 more than Tischer) and then finding some silicone sealant to bead around the DISA (why don't they just make a damn gasket for this thing??). Hopefully Friday I'll have it running and can test more then. This time I'll use INPA and get the BMW codes instead of these stupid P-codes.

Yes, please let us know how you make out this weekend. I have been considering putting some new silicone around the DISA.

Originally Posted by envoid

ok... I've concluded the DISA and CCV are ok but there might be an air leak between the DISA and intake manifold along with that pipe that was becoming brittle. Might be getting the pipe tomorrow from the dealer (only $2 more than Tischer) and then finding some silicone sealant to bead around the DISA (why don't they just make a damn gasket for this thing??). Hopefully Friday I'll have it running and can test more then. This time I'll use INPA and get the BMW codes instead of these stupid P-codes.

I replaced the pipe but didn't seal around the DISA opening. Currently, no light but had a P0171 code listed in INPA, and this is after the pipe was replaced and adaptations cleared.

One thing the car did yesterday was misfire or stutter. It did this after driving around 50mph for a bit and then stopping at a light. It kicked pretty hard to the passenger side, but it seems it was just once and guessing on one cylinder. It was really quick. Drove a bit more since and never did more of this. But there was no code from this.

I've gone through this site and I think my MAF is ok along with my O2 sensors, so that leaves another leak somewhere in the intake (maybe manifold gasket as I did replace that the first time I broke it down) and/or dirty/clogged fuel filter. I used INPA to activate the DISA and I hear it activating but will have to pull it and activate it while out to make sure it moves.

I'm probably going to pull the intake again and make sure the manifold gasket is ok and see about getting a fuel filter. INPA shows the pressure is ok but never know.

I need to find the meaning to some of the readings in INPA because the multiplier adaptation (i'm pretty sure it is the long-term fuel trim) is still high, though not as high as before, so I'm not sure if I have something else going on. The levels seem to rise only while driving and fall while idle or driving like grandma. I could really use another 330i E46 to get good readings off of to compare with. It doesn't really feel it's running right, like a little sluggish at accelerating and mileage is a little low still. But the pipe was a definite issue.

hello fellow e46'ers
my prob's are the same as all here. i too am getting double p0171&74 codes. I have taken off, checked, and replaced just about all under the hood, except taking off the intake. did all the ccv pipes, then took off and clean the maf and the disa. after putting disa back on i got the loud hissing noise like envoid. has anyone narrowed dwn the root cause of the two codes and now can you tell me why they double up. so lost any help or guidance will help and thanks in advance

sry, i have an 01 325i. the weather here in Atlanta has been kinda kold LOL

Originally Posted by envoid

I replaced the pipe but didn't seal around the DISA opening. Currently, no light but had a P0171 code listed in INPA, and this is after the pipe was replaced and adaptations cleared.

One thing the car did yesterday was misfire or stutter. It did this after driving around 50mph for a bit and then stopping at a light. It kicked pretty hard to the passenger side, but it seems it was just once and guessing on one cylinder. It was really quick. Drove a bit more since and never did more of this. But there was no code from this.

I've gone through this site and I think my MAF is ok along with my O2 sensors, so that leaves another leak somewhere in the intake (maybe manifold gasket as I did replace that the first time I broke it down) and/or dirty/clogged fuel filter. I used INPA to activate the DISA and I hear it activating but will have to pull it and activate it while out to make sure it moves.

I'm probably going to pull the intake again and make sure the manifold gasket is ok and see about getting a fuel filter. INPA shows the pressure is ok but never know.

I need to find the meaning to some of the readings in INPA because the multiplier adaptation (i'm pretty sure it is the long-term fuel trim) is still high, though not as high as before, so I'm not sure if I have something else going on. The levels seem to rise only while driving and fall while idle or driving like grandma. I could really use another 330i E46 to get good readings off of to compare with. It doesn't really feel it's running right, like a little sluggish at accelerating and mileage is a little low still. But the pipe was a definite issue.

Now that the weather is warmer...50F i havn't had any codes, but i still notice a little rough idle at stop signs and Stop Lights.

I have carsoft which does do live readings of different sensors, O2 and whatnot, i can get you my readings and see how they compare?

EDIT: My bro has a 03 330i, his next day off i may sway MAF's with him to see if anything changes