: Trouble Code P0420 ?



Carnut_s
04-16-12, 10:56 PM
I got this trouble code, P0420 on my 07 V so I took it into the dealership. They replaced the O2 sensor and cleared the code two weeks ago. It came back last night. The code is for Catalyst System Efficeincy Below Threshold ( Bank 1 ). Before I go back to the dealer can anyone tell me what would cause this code to come in. Thanks

GDPossehl
04-16-12, 11:00 PM
Perhaps a bad cat?

odthetruth
04-17-12, 12:16 AM
:yeah:

darkman
04-17-12, 07:04 AM
http://www.cadillacforums.com/forums/2004-2007-cadillac-cts-v-general/247945-catalytic-convertor-replacement-under-federal-emissions.html#post2807047

Cadillac Cust Svc
04-17-12, 12:47 PM
Sorry to hear about your frustrations, Carnut_s! When you get a chance, please let us know if the second dealer trip is able to provide you with a resolution.

Best,

Katie
Cadillac Customer Service