My dad has a 07 avalanche with the resonator and muffler delete. he has Had a check engine light it would be on one day then off one day. a buddy of mine has a scan tool so we scanned it and this code popes up P0420.
he was confused so, he ignored it until he had to get his front end fixed, and when we got his truck back and they said his catalytic converter is bad and needs fixing, and his air bag supention is blown. (it raises when under load) and his air bag light is on, with code is P0420 is that catalytic converter?
Well if you take out the muffler and the resonator the cat isn't going to work right because it's not going to have enough back pressure to keep the gases in long enough to burn the hydrocarbons you run a car with no muffler and resonator the cat will never work right
obd-codes.com
