# p0171 and p0174 issues



## Gto-noob (Nov 25, 2011)

car has 201,xxx miles 2006 m6 pacesetter lt, catlesss mids, SLP predator tune.vararam intake. bout a week ago car got p0171 and p0174 codes, car didnt act different in anyway still drove good, no loss of power. went camping for 3 days. got to my friends has and started driving home. car started running super rich i ended up getting 10.5mpgs got home, replaced MAF, cleaned tb, checked for vaccum leaks, intake leaks, cleaned spark plugs and regapped. threw in stock tune. problem still persists. oxygen sensors are about 10k miles old. during a warm start. car will idle perfect for ~30seconds and slowly start running more and more rich until it idles at 2.9gal/hour. if i rev and hold at any rpm ex- 1500rpm will stutter and drop to about 1200rpms. any thoughts or solutions would be great.


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## svede1212 (Nov 1, 2005)

I know it's obvious but either you're running lean from a leak or both front O2s are reading it wrong. Those are lean codes and you're running rich. The car should go in closed loop with the O2s keeping the fueling within range.


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## Gto-noob (Nov 25, 2011)

i replaced the 02 sensors probably 10k miles ago. and today i checked for vacuum leaks no sign of any leaks. you think it could be clogged fuel filter?


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## svede1212 (Nov 1, 2005)

Gto-noob said:


> i replaced the 02 sensors probably 10k miles ago. and today i checked for vacuum leaks no sign of any leaks. you think it could be clogged fuel filter?


Unlikely. The "filter" for what it is is in the tank. Sounds like your running rich which would be the computer is telling it to dump in fuel and it's able to keep up.


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## Gto-noob (Nov 25, 2011)

okay so not fuel pump/filter. wanna point me in a direction cause ive been checking for leaks all day


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## svede1212 (Nov 1, 2005)

Were you O2s OEM and wired up with the plugs they came with?


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## Gto-noob (Nov 25, 2011)

Yup. I have the driver side o2 using an extension due to the long tubes


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## Rukee (Feb 8, 2007)

Where did you buy the O2 sensors from??


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## Gto-noob (Nov 25, 2011)

rockauto


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## Gto-noob (Nov 25, 2011)

o2s are running at .60-.69v and the others are .01-.02
also looked at fuel pressure is around 55-58 and at idle needle moves rapidly between 50-60


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## Gto-noob (Nov 25, 2011)

also left fuel pressure tester on and shut car off lost 3-4psi in about 5-6minutes


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