Originally Posted by jk11blueboi
I had the same codes p0171 and p0174. After replacing both my 02 sensors (first i had po1133 and p01153 and p0101) cleaned the maf and got new o2 sensors and p0171 and p0174 were the only codes that would be pending and stick around. i went to autozone and baught the fuel filter for 10 dollars and it fixed the problem.
but it could also be a vacuum leak at your intake gasket. get carb cleaner while the engine is running and spray near the intake. if the idle changes, then u have a vacuum leak. goodluck
Do you have the 5.3L engine? Are there really only two O2 sensors on the engine? I've gotten codes, though I forget the exact numbers, but one says front bank and the other says rear bank. I'm not certain what the front and rear bank are.