CEL light with P0171 and P0102

SubaruWRXtreme · 03-11-2012, 05:06 PM

Hi guys couple of weeks ago I installed my cat back system on my 2009 WRX hatch and drove for a few weeks without any issues enjoying the sound of the exhaust. But lately the CEL came on and I scanned it and I got P0171 (System Too Lean) and P0102 (Mass or Volume Air Flow Circuit Low Input) then of course i cleared it but i comes back on after a few days then i decided to clean the MAF sensor and it was indeed dirty. After that little fix the car was driving much better and MPG- went up but guess what.... the CEL came back on anyway. The car drives just fine only at idle it fluctuates a little bit and i mean 100-200rpm you barely notice it.

But I'm all out of ideas, I'm starting to think that one of the 02 sensor is shot or MAF sensor is not working properly and triggering the CEL.

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SubaruWRXtreme · 03-17-2012, 02:38 PM

Anyone ?? LOL

jlmillionaire · 03-17-2012, 06:28 PM

I just threw a p0011 avcs can anyone help me with that?

SubaruWRXtreme · 03-17-2012, 06:53 PM

Quote:

Originally Posted by jlmillionaire

I just threw a p0011 avcs can anyone help me with that?

Your camgears-belt might might have skipped a teeth or two, have it checked quick !!

SubaruWRXtreme · 04-04-2012, 10:45 AM

Ok what helped solve my CEL P0171 and P0102 was just cleaning the MAF sensor, i used non-chlorinated brake cleaner always make sure it's non-chlorinated and sprayed both the temp sensors and MAF sensor wires. Did a tune up and cleared the CEL, it only showed the history of the CEL and that it was not the current CEL so i cleared it and all is well for 3 weeks now !!

BGPKR · 04-07-2012, 06:04 PM

I've been getting the same code on my LGT. I've cleaned the maf and it came back the next day. I'm thinking it's possibly the 02 sensor. Possible?

SubaruWRXtreme · 04-07-2012, 07:32 PM

It could be man, is the car idling fine or badly ??
My case I was worried it was the 02 sensor but the car idled just fine and drove just fine only the CEL came on. I reseted it and it came back then I decided to clean the MAF sensor with brake cleaner (non chlorinated) and gave the car a big tuneup changing oil and all the filters especially the fuel filter it might have been clogged and then reseted the CEL. Never came back on, I was worried because 2 weeks before I installed a CBE and the CEL I thought to myself damnit this can't be I didn't even touch the 02 or CAT.

If the car is idling rough or has bad performance and wasting gas it's probably the 02 alright.

Brandong · 02-19-2013, 02:10 PM

. I originally had a p0174 which is o2 sensor . I replaced the o2 sensor last month and it ran like brand new. 3 weeks later I got another cel, p0171. so I erased it. the code pops up about once a day now and I just erase the code. The only mod i have currently is Cobb sf intake, with access port running stage 1 91 octane stock map. I idle at around 1000RPMs. I've checked all my vacuum lines for leaks, cleaned my sensor with breaker cleaner, but can't find any problems with it. I can't see it being a o2 sensor again. But my car shakes like it is and the mileage is normal. Any ideas guys?

03-11-2012, 05:06 PM	#1
SubaruWRXtreme Scooby Newbie Member#: 307112 Join Date: Jan 2012 Chapter/Region: International Location: Curacao Vehicle: 2009 WRX (hatch) Satin White Pearl	CEL light with P0171 and P0102 Hi guys couple of weeks ago I installed my cat back system on my 2009 WRX hatch and drove for a few weeks without any issues enjoying the sound of the exhaust. But lately the CEL came on and I scanned it and I got P0171 (System Too Lean) and P0102 (Mass or Volume Air Flow Circuit Low Input) then of course i cleared it but i comes back on after a few days then i decided to clean the MAF sensor and it was indeed dirty. After that little fix the car was driving much better and MPG- went up but guess what.... the CEL came back on anyway. The car drives just fine only at idle it fluctuates a little bit and i mean 100-200rpm you barely notice it. But I'm all out of ideas, I'm starting to think that one of the 02 sensor is shot or MAF sensor is not working properly and triggering the CEL. * Registered users of the site do not see these ads.

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03-17-2012, 02:38 PM	#2
SubaruWRXtreme Scooby Newbie Member#: 307112 Join Date: Jan 2012 Chapter/Region: International Location: Curacao Vehicle: 2009 WRX (hatch) Satin White Pearl	Anyone ?? LOL

03-17-2012, 06:28 PM	#3
jlmillionaire Scooby Newbie Member#: 292740 Join Date: Aug 2011 Location: East Patchougue NY Vehicle: 2004 sti qrb/cf frnt cf rear bmp	I just threw a p0011 avcs can anyone help me with that?

04-04-2012, 10:45 AM	#5
SubaruWRXtreme Scooby Newbie Member#: 307112 Join Date: Jan 2012 Chapter/Region: International Location: Curacao Vehicle: 2009 WRX (hatch) Satin White Pearl	Ok what helped solve my CEL P0171 and P0102 was just cleaning the MAF sensor, i used non-chlorinated brake cleaner always make sure it's non-chlorinated and sprayed both the temp sensors and MAF sensor wires. Did a tune up and cleared the CEL, it only showed the history of the CEL and that it was not the current CEL so i cleared it and all is well for 3 weeks now !!

04-07-2012, 06:04 PM	#6
BGPKR Scooby Specialist Member#: 41842 Join Date: Aug 2003 Chapter/Region: MAIC Location: Morgantown, WV Vehicle: 2006 LGT LTD 5SM OBP	I've been getting the same code on my LGT. I've cleaned the maf and it came back the next day. I'm thinking it's possibly the 02 sensor. Possible?

04-07-2012, 07:32 PM	#7
SubaruWRXtreme Scooby Newbie Member#: 307112 Join Date: Jan 2012 Chapter/Region: International Location: Curacao Vehicle: 2009 WRX (hatch) Satin White Pearl	It could be man, is the car idling fine or badly ?? My case I was worried it was the 02 sensor but the car idled just fine and drove just fine only the CEL came on. I reseted it and it came back then I decided to clean the MAF sensor with brake cleaner (non chlorinated) and gave the car a big tuneup changing oil and all the filters especially the fuel filter it might have been clogged and then reseted the CEL. Never came back on, I was worried because 2 weeks before I installed a CBE and the CEL I thought to myself damnit this can't be I didn't even touch the 02 or CAT. If the car is idling rough or has bad performance and wasting gas it's probably the 02 alright.

02-19-2013, 02:10 PM	#8
Brandong Scooby Newbie Member#: 331008 Join Date: Sep 2012 Chapter/Region: NWIC Location: Everett, WA Vehicle: 2008 WRX Red	. I originally had a p0174 which is o2 sensor . I replaced the o2 sensor last month and it ran like brand new. 3 weeks later I got another cel, p0171. so I erased it. the code pops up about once a day now and I just erase the code. The only mod i have currently is Cobb sf intake, with access port running stage 1 91 octane stock map. I idle at around 1000RPMs. I've checked all my vacuum lines for leaks, cleaned my sensor with breaker cleaner, but can't find any problems with it. I can't see it being a o2 sensor again. But my car shakes like it is and the mileage is normal. Any ideas guys?