Running rich - BMW 3-Series (E90 E92) Forum

fndrh1st · 04-28-2011, 05:04 PM

Hey all,

Just tripped my check engine light. Ran i through my diagnostics, got the code P0172, which means im running rich. I have Bms power box and AFE CAI. I don't want to deal with blowing an O2 sensor or a cat conv. so should I clean the CAI and play it by ear, or should I just rip the thing out and not bother with it at all?
What do you think?

fdriller9 · 04-28-2011, 05:30 PM

Is the CAI oiled?

If so, try cleaning your MAF. With MAF cleaner.

overkill1125 · 04-28-2011, 06:59 PM

Its because of the AFE Intake. I had the dry version and it kept on throwing me the CEL with the same code.

I changed it back to stock and brought the car to dealer and they did many test and decided to change the MAF. All under warrantee

Kept it stock for 2 weeks and ran with no problems. Then I decided to put the AFE back in and the 3 days later the CEL was on with same code.

I changed it back to stock right away and a few days later the CEL turned off and everything was back to normal again.

Heard and read numerous problems with the AFE CAI. I decided to get the AFE oiled drop in filter and its running great.

No sound compared to the CAI but I get peace of mind!

TommyK · 04-28-2011, 07:37 PM

I agree the AFE intake does burn more gas and run richer. When i start my car up i can noticeably smell more exhaust fumes when its running versus when i have the stock airbox on. I have never had a CEL light come on and ive been using this intake since 2006 and 65k miles.

Logically this would make sense since the stock airbox does have charcoal filter for emissions control

fdriller9 · 04-28-2011, 07:58 PM

Quote:

Originally Posted by Tom@Modprojekt.com

Logically this would make sense since the stock airbox does have charcoal filter for emissions control

Yea but if you cut the charcoal filter out, it doesn't throw the CEL. I've had mine cut out for the past couple years. And it doesn't serve a purpose when the car is on, it prevents harmful gases from escaping when the engine is off. The reason why you smell more exhaust fumes at start up with the aFe is probably because you don't have the charcoal filter. I know that sounds backwards but I've noticed more exhaust fumes at start up after cutting my charcoal filter out. I've never had an intake on my car.

I don't see why this intake would cause a rich mixture. Running rich means too much fuel to air right?

Well if you have an intake supplying more air than the stock air box, than how does the car run rich if it's taking in more air? I understand that the car will adjust the A/F ratio and provide more fuel for the amount of air taken in, but the O2 sensor should lean the mixture out if it is detecting a rich reading, no?

Sounds like the MAF or O2 sensors are giving improper readings.

ska325xi · 04-28-2011, 10:01 PM

bms will run rich....when i had bms set at level3, exhaust fume smelled like gas, turn pbx off and now its alot better

now i only use throttle remap on bms

fndrh1st · 04-29-2011, 08:54 AM

My afe is the dry version.
Thanks for the feedback guys, i feel a little better knowing that other people have had similar problems.

I took out my cone last night- it was dirty as hell and had bugs and other things stuck within the slits. I haven't cleaned it since I got it, which was about 5k miles ago. So That must be my problem. I also cleaned my MAF. Put everything back in this morning, the CEL is off, and my car seems to be running very smooth.

Although I'm still skeptic about keeping both the bms and the afe in. overkill1125 mentioned peace of mind and I couldn't agree more. I rather know my engine is safe than have a little bit better sound and a tiny horsepower increase.

04-28-2011, 05:04 PM	#1
fndrh1st Enlisted Member Drives: 2007 328i coupe Join Date: May 2010 Location: WPB, FL Posts: 45 iTrader: (0)	Running rich Hey all, Just tripped my check engine light. Ran i through my diagnostics, got the code P0172, which means im running rich. I have Bms power box and AFE CAI. I don't want to deal with blowing an O2 sensor or a cat conv. so should I clean the CAI and play it by ear, or should I just rip the thing out and not bother with it at all? What do you think?
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04-28-2011, 10:01 PM	#6
ska325xi Major General Drives: 325XI Join Date: Sep 2005 Location: Boston Posts: 6,852 iTrader: (27) Garage List 2006 333 [0.00] 2006 325xi [0.00]	bms will run rich....when i had bms set at level3, exhaust fume smelled like gas, turn pbx off and now its alot better now i only use throttle remap on bms __________________ RPI Scoops, BMW Perf. Intake + Carbon Filter Removal, BMW Perf. Exhaust, PBX, CF Cowl Covers & Lower Snorkel, Matte Black Grills, Rep Hartge Lip, ///M Spoiler, BBS 219m + RE960pp, CF Wrapped Headlights, LUX 5.0 + Solaris Silvers, Vista DRL, Blacklines, Lic. Plate LED, 3M CF Di-Noc Trims, BMW Perf. Alcantara Steering Wheel + Alcantara Trim, ///M DCT Paddles, BMW Perf. Shift Knob + Boot, ///M Novillo Ebrake Handle + BMW Perf. Boot, ACS Pedals

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04-28-2011, 05:30 PM	#2
fdriller9 Banned Drives: '06 AW 330xi Join Date: Mar 2009 Location: North Jersey/Philly/NYC Posts: 7,092 iTrader: (4) Garage List 2006 330xi [3.22]	Is the CAI oiled? If so, try cleaning your MAF. With MAF cleaner.

04-28-2011, 06:59 PM	#3
overkill1125 Lieutenant Drives: 2013 328i xdrive Join Date: Jan 2010 Location: Montreal, Canada Posts: 530 iTrader: (4)	Its because of the AFE Intake. I had the dry version and it kept on throwing me the CEL with the same code. I changed it back to stock and brought the car to dealer and they did many test and decided to change the MAF. All under warrantee Kept it stock for 2 weeks and ran with no problems. Then I decided to put the AFE back in and the 3 days later the CEL was on with same code. I changed it back to stock right away and a few days later the CEL turned off and everything was back to normal again. Heard and read numerous problems with the AFE CAI. I decided to get the AFE oiled drop in filter and its running great. No sound compared to the CAI but I get peace of mind!

04-28-2011, 07:37 PM	#4
TommyK Brigadier General Drives: E90 335i LCI Join Date: Aug 2008 Location: Orange County, CA Posts: 3,327 iTrader: (9) Garage List 2009 BMW 335i LCI [0.00] 2006 E90 330i [0.00]	I agree the AFE intake does burn more gas and run richer. When i start my car up i can noticeably smell more exhaust fumes when its running versus when i have the stock airbox on. I have never had a CEL light come on and ive been using this intake since 2006 and 65k miles. Logically this would make sense since the stock airbox does have charcoal filter for emissions control

04-29-2011, 08:54 AM	#7
fndrh1st Enlisted Member Drives: 2007 328i coupe Join Date: May 2010 Location: WPB, FL Posts: 45 iTrader: (0)	My afe is the dry version. Thanks for the feedback guys, i feel a little better knowing that other people have had similar problems. I took out my cone last night- it was dirty as hell and had bugs and other things stuck within the slits. I haven't cleaned it since I got it, which was about 5k miles ago. So That must be my problem. I also cleaned my MAF. Put everything back in this morning, the CEL is off, and my car seems to be running very smooth. Although I'm still skeptic about keeping both the bms and the afe in. overkill1125 mentioned peace of mind and I couldn't agree more. I rather know my engine is safe than have a little bit better sound and a tiny horsepower increase.