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Discussion Starter #1
Basic info: 2009 fofo 2.0 mtx
Mods: air aid shot ram, and 2.5 custom cat back

Ok i have two of these cars one atx and the one in question mtx (same mods on both) now I checked the vacume and the arc was at 22-23 at idle and same with the mtx so I need to.find out what is making my car run lean

If any one might know why my code came up
 

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The fact that you're using a ram intake means that you are forcing air into a system that is normally only exposed to vacuum pressure from the engine, this is probably what is causing the engine to run lean (too much air). A tune will tell the computer to compensate for this difference by adding more fuel than what it thinks it should.
 

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Discussion Starter #3
Yea I was thinking that answer would come up it is just I would expect this to happen to both cars if that was the case

And my only agument with that answer is mass air flow sensor should measure air flow
 

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what was the exact code number?
 

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The fact that you're using a ram intake means that you are forcing air into a system that is normally only exposed to vacuum pressure from the engine, this is probably what is causing the engine to run lean (too much air). A tune will tell the computer to compensate for this difference by adding more fuel than what it thinks it should.
this makes sense but since both cars are modded the exact same way, the problem should happen to both.

a couple possibilities are that there is bad O2 sensor or the maf sensor is not measuring correctly or there is a vacuum leak after the maf.

with the maf sensor not measuring right the computer sees the improper air (lower than what is actually coming in) and thinks that it needs to meter back the fuel causing a lean condition.

With the O2 sensor scenario, a bad O2 sensor can be pin pointed by watching live datastream. the front O2 sensor should be fluctuating and the rear one should remain relatively stable. the front one will fluctuate because it is a narrow band sensor and the computer keeps adding and subtracting fuel to maintain a 14.7 AFR. the second one should remain relatively stable becasue it is after the cat and monitoring what comes out of the cat.

and a vacuum leak can cause a lean condition because there is extra air being introduced into the intake stream that was not accounted for my the maf sensor thereby causing the afr to be lean becasue there is not enough fuel in the mixture.(extra air that the maf does not "see")

My best guess is there is a vacuum leak after the maf. if you can rule this out then id start watching the datastreams for the O2 sensors and the maf sensor. most likely a vacuum leak.
 

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from what i have read on this forum, the manuals are more touchy when it comes to A/F codes(= just my 2 cents
 

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Code#?

Basic info: 2009 fofo 2.0 mtx
Mods: air aid shot ram, and 2.5 custom cat back

Ok i have two of these cars one atx and the one in question mtx (same mods on both) now I checked the vacume and the arc was at 22-23 at idle and same with the mtx so I need to.find out what is making my car run lean

If any one might know why my code came up
What is the code #? A tune would help that & make your car's more driveably too. & yes you will need 2 flasher's.
 

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This^^^ cant help without knowing the code!
 

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Discussion Starter #9
The code is a
P0171 system to lean bank one


I asked air aid and email crime one of there tecks :
While the AIRAID air intake does increase the amount of air available it does not force any additional air into the engine and should not create a lean condition when installed correctly. The throttle body determines how much is let in to the engine while the computer tells the injector how much fuel to put with it. Most of the time when a lean condition occurs after the installation of cold air intake it is due to a vacuum leak somewhere. The first thing we suggest in a situation like this is to double check all of the connections not only on the AIRAID air intake but al vacuum lines as well even on the other side of the engine as one may have been disturbed unknowingly during the install. Removing and reinstalling the intake is not a bad idea if the issue continues and make sure you disconnect the negative battery cable so the computer will start recalibrating to the new intake as soon as the engine is started. Hopefully this information will help you resolve this issue and please do not hesitate to get back in touch with me if you have any additional questions or concerns.

Mark Fowler AIRAID Filter Company
 

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Aurelius Pardus
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I didnt read through past the first few posts but I can tell you that ram air stuff is BS. Definitely not enough to lean out the system or we would all use it as a low boost turbo substitute.

that being said, check for a vacuum leak. Its possible to get this code if you also have a bad or failing intake manifold gasket. In some cases the first 02 could also be reading incorrectly.
 

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P0171 i just got one the other day, my SCT said on the description:

check for, not working MAF sensor( i cleaned mine), bad 02 sensor, dirty fuel lines,
i think i may have gotten it cuz i used 93 octane instead of 91 :/ but it hasnt came back on since i cleaned the MAF and put 91 back in it.
 
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