Just replaced all ignition coils due to error messages and rough running. Because I ran the car for about 30 Km's with faulty coils I may have damaged the O2 Sensor as I now have he check emgine light on and error message P0420 which indicates catalyst issues. Most times this is the bank 2 O2 sensor which needs replacing. Am I correct in my assessment? Any help is greatly appreciated

 

it can be a lazy O2 sensor, but chances are it's probably the cat.. It'd be helpful if we had the type of car, , year, mileage, etc...

 

04 Acura TL 3.2L with 291,000 Km

 

You can try and replace the O2 sensor or possibly even clean it but be prepared to shell out for the OEM cat if that doesn't work. Cats will fail if the engine decides to run rich for whatever reason and dump a bunch of unburned fuel into the cat. Sounds like the ign coils issue caused this cat error message.


If I were in your shoes, I'd try :

1. cleaning o2 sensor
2. if 1 doesn't work, replace with OEM o2 sensor
3. if 2 doesn't work, replace with OEM cat.

 

thank you thoiboi
i will try these and like you say, be prepared for the worst case scenario