I saw couple posting regarding code P0420, is this code refers to the cat behind engine, that's manifold and cat, there are two cat on the car, does bank 1 refers to cat next to manifold, I guess yes, parts is $350 on rockauto new, 300-400 on eaby used, should I get it replaced, it also could be 02 sensor. I need help. I read few postings, most of replaced by dealer, but my vt is 120K miles now, warranty doesn't work, so I have to pay. I'm thinking either fix now or no repair untill 2017 emission test, then get rid of the car. IL law require 1st emission test after 5 years on the new cars, so 2012-17 is 5 years, what do you guys think, replace manifold car or not, thanks
Tom
Tom