P0420 Fault Code on Emissions Test

2002 Chevy Venture Economy model, Catalytic Converter appears to be original, have 125,000 Miles on it and it is a little noisy. Have heard it could be either of the 2 O2 sensors, but probably a bad cat, right? Anyone else? How long should it take a mechanice to replace a Cat on this model?

Had the P0420 pop up for a few years before I had Menike repace the cat, haven't seen the code since. Dropped if off but most likey only took them an hour or so. Think it was ~$220. Think it started popping up around 150,000 miles or so.

I would replace the CAT, and upstream H20 sensor for the air/fuel mix only, the old upstream H02 sensor canbe used down stream.

www.catalyticconverterwarehouse.com (http://www.catalyticconverterwarehouse.com) has OEM for $219, aftermarket cats are alot cheaper.