BerserkerJack

So I got the 05. 2500. Burban with the 8.1 delivered last week. Eng light came on. Plugged up to the code thinggie, and "catalytic converter / bank 2" is the reading. Anyone with some 1st hand knowledge on this topic? So, AutoZone shows one catalytic converter for $596, then right beside that one is a "universal" catalytic converter for $71. That's a pretty big difference, right? Or do I even NEED to swap it out? Could it be a sensor? Im in SC where we don't do vehicle inspections any longer ..... Can the catalytic converter just be bypassed?

oldchevy

I would not use the universal one. Check out Rockauto or other online sellers for much better prices. Does it run good and get the gas mileage it is supposed to get?

BerserkerJack

Yeah, it's running just fine. Mileage is better than I thought it would be.

oldchevy

What is the exact code you are getting?

BerserkerJack

Code P0430 .... Catalyst System Efficiency Below Threshold (BANK 2)

oldchevy

I would take a chance and replace the downstream O2 sensor on bank 2. it is a lot cheaper than a cat and there is a good chance that it will work. Are there any other codes beside P0430?

BerserkerJack

No sir, thats the only code, and no other dash lights.

tech2

check and see if a new 02 is on the back and old 02 is on the front. this can cause a low efficiency dtc if the front sensor is switching slow. the fix is to replace the front 02. if all 02 are switching normally ...it needs a cat.
on a properly functioning system the fronts should switch faster than the rear. cats that no longer reduce hc, the rear 02 switch at the same rate as the front 02. rev teh engine up to 2000prm and monitor the 02 switch rates at that rpm

don't buy a cheap cat or it will reset low efficiency dtc.