E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > Tuning & Tech > Driveline, Engine & DME Tuning

Driveline, Engine & DME Tuning
Talk about driveline improvements, NA tuning and DME tuning your E46 BMW here. This includes diffs, intakes, exhausts, chips, software and OBD tuning.

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 12-13-2011, 05:24 PM   #1
Sean172
Registered User
 
Join Date: Jul 2009
Location: Mahopac, NY
Posts: 26
My Ride: 03' 330i
Service Engine light wont go away - Bank 1 & 2 too lean?

Help!! My engine began running rough and the service engine light has been on. I have cleaned my Mass Air Flow sensor, been throught a dozen bottles of injector cleaner, and I just replaced the two upstream oxygen sonsors. The engine still idles rough and the OBD code shows Bank 1 sytem too lean, Bank 2 system too lean, as well as a slew of random misfire codes. What the hell!!! What should I do next? Any suggestions
Thanks
Sean172 is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.
Old 12-13-2011, 05:31 PM   #2
thekidba
Registered User
 
Join Date: May 2011
Location: Long Island
Posts: 37
My Ride: 2000 323ci
Same thing happened to me. I have a thread about it somewhere here, but it turned out to be the MAF. Cleaning it doesn't work after awhile and it needed to be replaced. Replace those hoses if they're brittle since your in the vicinity. gl
thekidba is offline   Reply With Quote
Old 12-13-2011, 05:35 PM   #3
Sean172
Registered User
 
Join Date: Jul 2009
Location: Mahopac, NY
Posts: 26
My Ride: 03' 330i
I was thinking the same thing,

I cleaned it twice, the first time I didnt see that there were two sets of wire filaments is the sensor and I only cleaned one. After I cleaned it correctly the car ran much better, I almost thought I had it licked but it started idling poorly again. But I think I am on the right track with the MAF sensor. Thanks
Sean172 is offline   Reply With Quote
Old 12-13-2011, 05:41 PM   #4
TxZHP04
Registered User
 
Join Date: Feb 2006
Location: DFW
Posts: 5,728
My Ride: ESS TS2+ ZHP
More than likely you have a vac leak. Quit messing with the MAF and find the leak.
__________________
04 IR 330i ZHP | ESS TS2+ SC | MagnaFlow "headers" | KMS 3.64 LSD | AST 4100 550/650| APEX ARC-8 18x9 | H&R front sway bar | Vorshlag camber plates, RTAB limiters | TMS subframe & swaybar reinforcements | UUC SSK & DSSR | UUC TM & TME | BW motor mounts | Dinan strut & shock tower bars | vaio 4-bolt oil pump
TxZHP04 is offline   Reply With Quote
Old 12-13-2011, 06:57 PM   #5
Sean172
Registered User
 
Join Date: Jul 2009
Location: Mahopac, NY
Posts: 26
My Ride: 03' 330i
How do find a vacuum leak?

How do find a vacuum leak?
Sean172 is offline   Reply With Quote
Old 12-13-2011, 08:08 PM   #6
jordangreen21
Registered User
 
Join Date: Oct 2010
Location: North Carolina
Posts: 165
My Ride: e46 m3
So I am having a similar problem... I was running catless headers and everything was running fine. I installed my stock headers again and am having these same codes thrown. Everything was fine before... is it just a coincidence that I am now having a vac leak because that is what I keep seeing people say about having similar problems.
__________________

D2 Racing Sport Suspension ~ aFe CAI ~ AA Tune ~ Orion AEs ~ Topspeed Exhaust ~ Euro Headers ~ UUC SSK Evo 3 and DSSR ~ 15% Tint Windows and 50% Windshield
jordangreen21 is offline   Reply With Quote
Old 12-14-2011, 07:43 AM   #7
TxZHP04
Registered User
 
Join Date: Feb 2006
Location: DFW
Posts: 5,728
My Ride: ESS TS2+ ZHP
Quote:
Originally Posted by Sean172 View Post
How do find a vacuum leak?
A professional smoke test is your best bet. Sometimes you can find these leaks through visual inspection or strategic spraying of volatile fluids around the engine bay. Plenty of discussion of this topic including a thread on how to build your own smoke machine, you just need to search them out. Cracks in the intake boot between the MAF and TB are pretty common as are cracks in the numerous hoses attached to the intake manifold. A leaking DISA gasket is also relatively common.
__________________
04 IR 330i ZHP | ESS TS2+ SC | MagnaFlow "headers" | KMS 3.64 LSD | AST 4100 550/650| APEX ARC-8 18x9 | H&R front sway bar | Vorshlag camber plates, RTAB limiters | TMS subframe & swaybar reinforcements | UUC SSK & DSSR | UUC TM & TME | BW motor mounts | Dinan strut & shock tower bars | vaio 4-bolt oil pump
TxZHP04 is offline   Reply With Quote
Old 12-14-2011, 01:41 PM   #8
Sean172
Registered User
 
Join Date: Jul 2009
Location: Mahopac, NY
Posts: 26
My Ride: 03' 330i
Found a leak in intake boot

I followed the suggestion about tracking down a vacuum leak and BINGO!! Both of the boots on either side of MAF sensor were dry rotted on the back sides out of sight. The rear one has a branch off to the idle control valve, that one had a huge hole in it that I could fit my index finger in. Getting that one off looks like a bitch, it has a hose clamp holding it on which is buried under the throttle body. Is there a DIY on this??
Thanks for the tips!!
Sean
Sean172 is offline   Reply With Quote
Old 12-14-2011, 02:26 PM   #9
CylonRed
Registered User
 
Join Date: Jun 2010
Location: SW Ohio
Posts: 784
My Ride: '01 E46 330i sport
Quote:
Originally Posted by Sean172 View Post
I followed the suggestion about tracking down a vacuum leak and BINGO!! Both of the boots on either side of MAF sensor were dry rotted on the back sides out of sight. The rear one has a branch off to the idle control valve, that one had a huge hole in it that I could fit my index finger in. Getting that one off looks like a bitch, it has a hose clamp holding it on which is buried under the throttle body. Is there a DIY on this??
Thanks for the tips!!
Sean
Many DIY's - not that hard to do but I did need a mirror to see to make sure I lined up the intake properly.
CylonRed is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Censor is OFF





All times are GMT -5. The time now is 03:06 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
(c) 1999 - 2011 performanceIX Inc - privacy policy - terms of use