I have a 2006 Pilot 189000 miles. I'm getting a code Po420. Plenty of power, np bad smells, cats don't seem to be excessively hot,
I took it to the dealer. they said main rear cat is bad under the vehicle. I went to the parts department at the dealer the said the main rear is bank 2 by the firewall. po420 is bank 1 by the radiator? fuel trim is all over the place, from -6 to +6. this is a california emissions vehicle, if I need a cat can I put a federal emission instead of a Calif without messing up the computer?