I have a 2006 Mustang GT and as of late it’s been throwing codes (P0420 and P0430 - catalyst efficiency below threshold both bank 1 and 2). I had it into the dealer (since it was initially hard to cold start and would produce smoke), the dealer said it was due to my AFE Stage 2 intake and oil filter which was over oiled and as such some of the oil had transferred onto the MAF sensor. They cleaned it and I had the same problem again, this time I purchased the AFE dry filter, sensor cleaner & throttle body cleaner and went to it on my own and cleaned everything out before reinstalling the dry filter, clearing the codes (oh btw I have an Xcal with Brenspeed tunes). Upon taking everything apart I noticed that the rubber seal between the throttle body and the intake had been significantly over tightened and over time had developed a crack. Could this be the culprit of the check engine light, rougher/higher idle etc.)? I’ve looked for a part number but haven’t had any luck searching for throttle body gasket (and TB seal), does anyone know what the part number is?<o></o> Thanks,<o></o> Matt<o></o>
Do you have an Off Road H/X Pipe installed on your car? If you do, I think these codes can come up if you don't get the Rear O2's turned off in your computer program. If you don't, I think I remember hearing that air leaks on the Intake, MAF, couplings, etc, can create DTC's as well.
Yes. If the engine is taking in unemetered air then the o2's will read more oxygen in the exhaust and set off that code.
