bigwerm187

So ive been having a problem with this code p0171. First I had a rough idle and I was able to narrow it down that it was a bad pvc valve. So i Replaced it. Code went away for a few weeks and now its back. But my idle is no long rough tho and my TL runs fine with out problems but this Code keeps on coming back. How can i test my sensors and all that fun stuff..? Has anyone had this problem as well..??

winn808

Here are some of the main causes for the code p0171

The MAF (Mass Air Flow) Sensor is dirty or faulty
Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
There could be a vacuum leak downstream of the MAF sensor
Possible cracked vacuum or PCV line/connection
Faulty or stuck open PCV valve
Failed or faulty oxygen sensor (bank 1, sensor 1)
Sticking/plugged or failed fuel injector
Low fuel pressure (possible plugged/dirty fuel filter!)
Exhaust leak between engine and first oxygen sensor

Its funny how we both got similar problems but yet their totally different causes

bigwerm187

How could i test my maf sensor or oxegen sensor.

I know its not a fuel issue cuz my motor runs stright and i replaced my pvc valve cuz i had rough idel and it was stuck closed... And how could i find a crack hose if i can see them cuz i checked them already..

winn808

was your rough idle when you first cold start your car? I have that problem too.

As for the MAF Sensor testing, using a multimeter to check the ohms rating on the connector will probably work. i've tried doing it, but still having the same problem

BTW where is the pcv anyways. i'm looking for it but cant seem to find it. you got a picture?

bigwerm187

Well it was only at idle no matter if it was cold or running temps. the PVC is that plastice elbow looking thing on your valve cover. lol u cant miss it. yeah but what are the ohms that its suppoes to be at to know if the maf is cool or not..???.. and wjhat wires do u test on the maf......