2001 Infiniti QX4 with P0420 and P0430

Hi All,

Well, my vehicle failed it's MA Emissions Inspection due to P0420 and P0430 error codes.

I took the vehicle to a MA registered Emissions shop and he confirmed that the cats were bad. He did provide a TSB about the ECM needing to be reprogrammed before trying to replacing the cats. I've left a message with the guy to find out if he tried reprogramming it or if it's something the dealer needs to perform but he's out til next monday.

Sadly, my car is at 84k miles and pass the 80k federal emissions warranty. Neither the dealer or Infiniti consumer affairs will help me out. The cost to replace both cats is $1.8k and higher(based on where I take it).

Curious, b/c my SES (Service Engine Light) did not go off, could it possible be a ECM problem and reprogramming will fix it? If yes, can a dealership only perform this?

Thanks for any help.

edit - fwiw, I had all four O2 sensors replaced a year ago with the SES went off.

likely dealer only reprogramming, some aftermarket 02 sensors are junk!