Quote:
|
Originally Posted by KimMG
misfire could be caused by bad spark plug wires.
|
Based on the excessive lean condition on both cylinder banks, I suspect that I will need to replace the plugs and wires at any rate (88k miles), but I think this is caused by the computer trying to richen up the mix. I don't think it is the root cause of the problem. I expect to find fouled plugs due to an excessively rich fuel trim. An excessively lean condition code being latched tells me the computer has used the entire range of injector pulse opening to try to fatten up the mixture, but still failed. So either I am injesting more air into the cylinder than is being detected by the MAF sensor (indicating a leak somewhere after the MAF), or the MAF sensor is malfunctioning. I thought OBD2 was supposed to catch failing sensors.
I am ruling out Oxygen sensors at this point. My understanding is that upon cold start, the system operates in Open loop, and does not use o2 sensor input for fuel trim.
Any other input would be appreciated. And thanks KimMG.