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-   -   Lean codes driving me nuts! Help! (http://forum.e46fanatics.com/showthread.php?t=955680)

E46Zone 11-12-2012 09:46 PM

Lean codes driving me nuts! Help!
 
Hello all, I'm on here asking for all your cumulative assistance to help me solve these codes that ive been getting.

-Lean codes P0171 & P0174
- P0131 Misfire due to low fuel
and P0505 ICV failure

The codes are intermittent and randomly trigger the SES light and vice-versa. The car runs perfectly and idles well the only thing noticeable is the decrease in MPG.

So far I've:
-Cleaned MAF
-Changed both intake boots
-New VCG not so long ago
-New fuel pump and fuel filter (2 days ago) along with new fuel hose and vac hose
-New Disa (old one was torn up)
and i've Cleaned the ICV
I also checked the oil drain hose from the CCV and it was fine/not broken

any help would be greatly appreciated! TYIA!

Mflara20 11-12-2012 09:54 PM

Check all the rubber hoses specially the one where the brake booster goes, mine was not even plugged due to the poor design. I bought a better design (one that connects both hoses securely) and all my lean troubles went away

TrippinBimmer 11-12-2012 09:55 PM

Quote:

Originally Posted by Mflara20 (Post 14894341)
Check all the rubber hoses specially the one where the brake booster goes, mine was not even plugged due to the poor design. I bought a better design (one that connects both hoses securely) and all my lean troubles went away

Pics?

E46Zone 11-12-2012 10:01 PM

were you getting misfire codes as well? and would a dirty throttle body cause lean codes as well seeing as I just cleaned the ICV and not the throttle body.

Mflara20 11-12-2012 10:45 PM

I dnt have a pic right now but of you look where the two hoses connect there's a connector and there's a updated version that's fits so tightly with no leaks.

Mflara20 11-12-2012 10:54 PM

Here's the link, I just used the new connector.

http://item.mobileweb.ebay.com/viewi...d=110731572088

jfoj 11-13-2012 05:44 AM

Assume you have read the first link below in my signature?

Are you sure the CCV lower oil return hose is good? If you have a cold weather hose, with the insulation, it will many times hide the bad hose. If the hose is covered with oil, it is bad.

You may have other bad CCV hoses as well.

MAF cleaner only works for MAF's that have oil on them. You could have a bad MAF or a non-OEM MAF that is under reporting the air flow. Usually a bad MAF will trigger the CEL at a cruise and not idle.

Even though you changed the valve cover gasket, you could have a cracked valve cover. Lots of small vacuum hoses under the rear of the intake that can get disconnected or go bad.

You have to figure out if you have a crankcase air leak, a vacuum leak in the intake path or a bad MAF under reporting the airflow.

Do you have the ability to read the MAF Grams/sec airflow and fuel trims? This may help, otherwise a smoke test may be needed.

Smoke test both the intake path and the crankcase.

E46Zone 11-13-2012 12:56 PM

Quote:

Originally Posted by jfoj (Post 14895037)
Assume you have read the first link below in my signature?

Are you sure the CCV lower oil return hose is good? If you have a cold weather hose, with the insulation, it will many times hide the bad hose. If the hose is covered with oil, it is bad.

You may have other bad CCV hoses as well.

MAF cleaner only works for MAF's that have oil on them. You could have a bad MAF or a non-OEM MAF that is under reporting the air flow. Usually a bad MAF will trigger the CEL at a cruise and not idle.

Even though you changed the valve cover gasket, you could have a cracked valve cover. Lots of small vacuum hoses under the rear of the intake that can get disconnected or go bad.

You have to figure out if you have a crankcase air leak, a vacuum leak in the intake path or a bad MAF under reporting the airflow.

Do you have the ability to read the MAF Grams/sec airflow and fuel trims? This may help, otherwise a smoke test may be needed.

Smoke test both the intake path and the crankcase.

Hey, jfoj

Yeah i've read your first 2 links (very useful info) which is why I changed my fuel pump which was the original with 163k miles.
I've physically grabbed the oil return hose and checked both sides of the connections and they felt fine, no oil on them as well.

I also read on another thread that by blowing down the oil dipstick you could check some CCV hose if the oil bubbled? Regardless I did this and my oil did indeed bubble. About an hour ago I went back in to clean up my ICV which I cleaned about ~a month ago and it was stuck and not freely moving until I sprayed it down. I also changed the vacuum hose from the 'F' connector that goes to the fuel filter.

With regards to the MAF, about 2 months ago I ordered a non-oem MAF (big mistake!) when I was initially getting the codes, the non-oem MAF caused my car to stall out at a light and idle horribly, I put my old MAF back in ASAP and the car ran fine.

I also had the car smoked when the codes first came up and the culprit were the 2 intake boots- which got changed and some hoses.

I dont have anything to measure the fuel trims, but im assuming its throwing more gas then it needs considering 3 days ago when the light came off, the car was getting ~20.6 MPG, yesterday when the light came on it was dropping and when I checked it was at 19.4 MPG, same driving style and route.

E46Zone 11-13-2012 01:20 PM

3 Attachment(s)
In response to the brake booster hose, I also checked it and it wasn't disconnected nor seemed torn, although it did have some play towards the top connection.

As I was looking around the car I found these 3 things that could be a possibility to the codes?

The first picture is the hose that comes off the SAP

The hose that comes off the air pump is very old and cracked Im not sure if this can cause lean codes :hmm:??

and the last picture is from when I took the car to get the VCG changed, apparently they tightened the bolt to much and it cracked the plastic, they put sealant on the crack probably thinking I wouldn't notice.

jfoj 11-13-2012 02:33 PM

Big SAP will not cause lean codes, but should be replaced. Cracked valve cover is likely your main problem.

E46Zone 12-12-2012 11:29 AM

1 Attachment(s)
Update: I sealed up the cracks on the valve cover with some RTV sealant until I can replace the valve cover itself; Driven the car a good couple hundred miles now and low and behold no more lean codes :clap:, thanks for all your help guys appreciate it :thumbsup:


Also; I just changed out the CCV system and noticed the oil drain back hose was clogged, so it was only a matter a time for another lean code or catastrophic failure :eek:.

jfoj 12-12-2012 11:33 AM

The old cracked plastic valve cover rears its ugly head again!

E46Zone 12-12-2012 11:40 AM

Quote:

Originally Posted by jfoj (Post 14973170)
The old cracked plastic valve cover rears its ugly head again!

YES! lol, actually I took the car to an indy a while back to get the VCG changed, (before I knew about this wonderful site) and they actually cracked the cover from over torque.

jfoj 12-12-2012 11:52 AM

Stay aware from Victor Rienz gaskets, get them from an online BMW dealer.

Also use Prematex Ultra Black at the corners and on the half moons. Only a small bit on the half moons, a bit more in the corners.

Hand torque carefully, 1/4" ratchet is best, slightly beyond snug.


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