Error Code P0420

[homermacleod]

When I looked up the code, it says it could be the catalytic converter or the oxygen sensors.

How can I determine which one it is before replacing them? The catalytic converter was just changed in September 2009 (magna flow).

Also, besides the ease of installation with the bolt on, is there any advantage to buying the bolt on magna flow cat instead of the universal?

Bolt on: http://www.magnaflow.com/02catalyti...irectfit01.asp?catalogid=5501&directfit=23457
Universal: http://www.magnaflow.com/02catalyti...versal01.asp?catalogid=5541&universal=99009HM

 

[JonZ71]

does your exhaust smell horrible like rotten eggs? if yes it's a cat, if not a o2

 

[homermacleod]

I don't think so, but I will make sure tomorrow.

 

[JonZ71]

unplug your o2 sensors and see if it's the same code. im gonna bet it's the rear one.