jim ashton
Member
- Joined
- October 8, 2001
- Messages
- 20
- Reaction score
- 0
- City, State
- warren, michigan
- Year, Model & Trim Level
- 96 sport
my engine light came on and the code reads P0420=catalyst efficiency below thershold bank 1, then in the manual it reads further as monitor and/or exhaust system fault my question is i have replaced both 02 sensors on the exhaust system is there a "monitor" somewhere else. i have also had the exhaust checked it the muffler shop i took it to said it was fine. any ideas?
