I keep getting the P0420 code and each time I reset the ECU it comes back after 500 miles of driving. I realize the code is telling me the bank 1 catalyst is below efficiency, but I don't have cats and during my dyno tune my tuner shut off the rear O2 sensors.
What else could be causing this to happen? I recently replaced the IAC motor, I cleaned the MAF, I've checked for vacuum leaks and haven't found anything, there are no exhaust leaks, and the PCV valve was replaced last week (though not sure if it would have anything to do with this).
Now there is another issue here. My car won't idle well once its warmed up. I thought it was an IAC problem, but even after replacing the IAC it still doesn't idle well. If I come to a stop after the car has warmed up the RPM's bounce between 500 and 1300 and sometimes the car dies. If it doesn't die, the RPMs settle around 900. WTF?
What else could be causing this to happen? I recently replaced the IAC motor, I cleaned the MAF, I've checked for vacuum leaks and haven't found anything, there are no exhaust leaks, and the PCV valve was replaced last week (though not sure if it would have anything to do with this).
Now there is another issue here. My car won't idle well once its warmed up. I thought it was an IAC problem, but even after replacing the IAC it still doesn't idle well. If I come to a stop after the car has warmed up the RPM's bounce between 500 and 1300 and sometimes the car dies. If it doesn't die, the RPMs settle around 900. WTF?