Need Help with Pin Pointing OBD Code P0171 Chevy Trailblazer 2007 V6
 

Hello,


For a little over a month, P0171 (System to Lean) code comes up. My brother has cleaned the throttle and the MAF. It then worked fine for a few weeks, then the code came up again and the sputtering started. He took it to O' Reilys Auto Parts. They had said since you removed the throttle and put it back in, it would need to retrain itself. He then removed it again and cleaned out other parts in the car. Just the other day, my car started sputtering again in the morning. It runs fine the rest of the day. Also, when I was out of town the other day, my car sat for about 4 days with a low tank of gas. When we were traveling on the highway, my reduced power engine light came on. Once I filled up with gas it was fine. I am just trying to see what could be the problem. Do I need a new O2 sensor, a change of the manifold gasket, fuel injector cleaning. Not sure. The car is good to drive, but would like to fix this problem.

the throttle body won't cause a lean condition.


what engine?
is the fuel trim lean on both banks or just one...check with a scan tool. both banks may be lean but it may be setting just one code.


check the fuel trim on both banks when in closed loop (warmed up) at idle and held at 2500rpm. report the results.

It is lean on 1 bank. Someone mentioned to me, that my fuel injectors may be clogged and need to be cleaned.

Ya, I got that...its lean. I need to know the live fuel trim readings to be able to help you.




clogged injectors; its possible but rare. lets rule the more common issues before going there.