You know, I feel the MAF and O2 sensor issues are related. Do you have access to a scanner that can read real time data?
If you have the actual code numbers, for example, P0137, that would really be helpful. I have pages of tests to go through and can't do it without the codes. Since you haven't replaced the MAF, it may be the issue. First, check the following:
Air intake - objects blocking throttle body inlet screen
Intake Manifold leaks
Vacuum leaks at throttle body
Air leaks at EGR valve flange and pipe
Crankcase ventilation valve faulty, missing, or incorrectly installed.
Also, check the brake booster vacuum supply for leaks.
IF they all check okay, then this is where I need to know what codes you found. For example, does it have a P0121? That would indicate throttle position angle is not near 0 and certain things need checked. If it is near 0, then I have to go a different direction. Without the actual codes, we could spend weeks going through things.
Let me know.
Sunday, August 3rd, 2014 AT 10:53 AM