Almost exactly when i hit 88,000 miles on the truck, the check engine light came on, but truck still runs normal. Used the superchip and code was P0430 Catalyst efficiency(bank 2). Though of u who had had this code b4 or familiar w/ it, was it the cat or the o2 sensors? Also did a search on here & came to conclusion it's passenger side cat or sensor, please correct me if wrong. Thanks

 

Yeah this is a downstream (after the cat) sensor. The code in itself will cause NO drivability issues, but if the cat is clogged, that will.

There are only three possibilities as to what is wrong.

1) The cat is clogged and needs replacing.

2) The O2 sensor is shot.

3) There is an exhaust leak that could be anywhere from the exhaust manifold to the sensor.

It's usually the sensor, but this would be MY plan of attack:

Do a visual inspection of the exhaust and look for a sign of a leak. It's VERY common that road vibrations can snap an exhaust manifold bolt which would generate this CEL.
If there are no visible problem, replace the O2, they are cheap enough and even if it's NOT the problem, a fresh O2 sensor often increases fuel economy a tad.
If this doesn't fix it, it's time to look into a new cat...

 

Thanks for the detailed info. I'll check it out Sunday, and if it is the cat, do I replace just the pass cat or both? If I just replace the 1 cat it would have to be OEM to match the non shot cat. The code is for the passenger side correct? Thanks again