I just got a 02 Z28 6 speed and 2 days after my check engine light came on i checked it out and on the OBD2 scaner came up with catalest below thershhold bank 1 what do you guys think??? is it the O2 sensor?

 

If you know the code (ie P0422) then you can do a google search.

It sounds like the O2 sensor after the catalyst (or lack thereof). Check connections first. It could actually be the converter itself but less likely.

Regards

 

Code P0420? Lot's of info on this - click search button in this forum and type in the code. My money is on a bad cat if you're stock. Welcome to the board.

 

Before calling it a bad cat, I'd check the sensor. Switch the sensors behind the cats. If the problem stays on the same side, it's most likely the cat (but could be the connection). If the problem follows the sensor over to the other side, then it's most likely the sensor.

 

Well like an idiot i reset the code so its not there any more but i guess if its bad it will come up agean

 

Above is a proven and the best/cheapest way to determine what's really wrong.

 

I dont mean to hijack the thread, but is bank one the driver side?

 

Yes bank 1 is driver side, bank 2 is passenger.

 

try hitting the cat you think is bad with a rubber mallet, if it rattles it's junk if not then it's possible it's still good. Now don't think if it doesn't rattle that it's not bad either, and don't smash it, just hit it kinda lightly.