P0171 System Lean (Bank 1), Knocking, Low Idle
I recently failed my emissions with a P0171 code. I know this could be a lot of things, but there are some other symptoms that go along with the problem.
My engine has a faint knocking that sounds like a misfire. I tried higher octane gas and the sound kept on.
I idle rough down at 500-600 rpm's, and have stalled in the past. I changed the fuel filter and that helped with the stalling, but there is still some occasional hesitation. Once I get going it runs great, but my fuel mileage is down to 15-16 MPG highway.
I cleaned the MAF and throttle body tonight, but I am sure there is more to all this. I am going to get a new hose for my PCV valve because it seems to fit over the valve pretty loose.
What else do I need to do?
Also, I disconnected the neg. terminal to take off the MAF and of course the CEL went off and the code is cleared. How long or far do I have to drive before I know whether or not the problem is fixed?
I know I'm throwin' a bunch at y'all, and I appreciate any feedback.