Im still trying to find a way to work around my P0420 problem.

I reworked the exhaust after some input from some other members (put the resonator where the cat. used to be and put a spacer in to pull the O2 sensor a little out of the flow) but that still didnt work.

im wondering what parameters need to be met for the ECM to run the test. im thinking maybe i can work around it, possbly set things up so one of the requirements is never met, possibly increase idle rpm?