I bought a 2006 Charger RT last week. The check engine light keeps coming on and I keep clearing the Codes every 2 days. Code P0420,P0430. (Catalyst system below threshold bank 1 and 2)
Brought the car in today for e test and it passed. but engine light came on again tonight on the way home. The guy who had the car before me installed 3" stainless steel pipes from the cats back with new HP cats and flowmaster mufflers no resonators or crossover. nice job sounds great. Also have a digital wide band installed usually reads between 13.5 - 15 Anyone have any idea about the engine light. Thanks
Doug

 

3" ?? You lost your backpressure by having the new exhaust installed. The exhaust content going by the O2 sensors will be mixed and erratic at times. These codes will always keep coming back.