Thanks for the reply!
No, none of those things you mentioned has happened over the last year, but something did cause the P0420 code to come up in only 3 months after putting the new converter on.
I do remember asking a different mechanic about it and he told me the 'wrong' type of converter for my car was put on. He said it was an old type. I didn't really know if I should take him seriously, but it sounds like what you are saying about the aftermarket CAT vs. The OEM. (What's an OEM?).
I wonder why the converter that was put on let me pass at all then before it caused the code to come back up.
Friday, July 31st, 2009 AT 4:00 PM