I believe it is at idle or cruising...what is the engine rpm at freeze frame of the code?
P2177, possibilities are...
1)Engine misfiring
2)Faulty O2 readings
3)Air leaks in the intake, post MAF
4)Low fuel pressure
5)Fuel injector failing
6)MAF sensor faulty
...so, you can eliminate 1, 3, 4, and 6 correct? Then you're left with 2 and 5. I'd choose to swap in a new O2 before injectors. If you do the new O2 and find nothing is corrected...you likely need injectors. When off and cleaning them, did you run them in for testing? If you believe them to be fine...then number 5 is now eliminated and you are left with just the O2. :thumbsup:
It is happening when cruising yes.
Code went away in the spring as fuel trims dropped below 20. Car still is running lean (currently at 12) but no CEL anymore.
1) no misfires
2) O2 sensor was the second part I replaced
3)possibly, but nothing showed up during several smoke tests and pressure tests
4)never had low fuel pressure and I have replaced all fuel pumps, sensors, filter (huge waste of money)
5)I don't think it applies as I'm not getting misfires. I have pulled and cleaned the injectors recently when I cleaned the intake valves.
6)MAF was actually the first part I replaced when all this started.
The car runs OK now as I guess it can compensate pretty well at 12 LTFT. We'll see what happens when it gets cold again.