Monguse01TA

Hi all. I was hoping some of you could help me figure out a problem and solution. I keep getting a recuring "Catylyst SYS efficiencency below threshold bank (2)" error code. I've replaced the O2 sesors before and after the CAT and still get the same code. I currently have brand new O2s on bank 1 and 2, before the CATS, and original equipment, after the CATS. I'm thinking that I need to replace the CAT on side 2, but can't figure how it went bad after only 29,000 miles. What do you guys think?

2001NBMZ28

Most likely it IS a bad passenger side cat (P0430). Friend of mine had his driver's side (P0420) replaced free at 20K by the dealer under the federal emissions 8yr/80K warranty. Don't know why it went bad but you can find more info if you search for the codes in the PCM diagnostics and tuning section.

mrr23

iTrader: (3)

it's the CAT itself. hence the low CAT efficiency code P0430 i've had both replaced under warranty on the 00 formula.

GM Muscle

iTrader: (9)

GM is notorious for junk cats. My Camaro lost the drivers side at about 15,000 miles, and my Silverado just lost the drivers side at 55,000 miles. Bring it to the dealer, cats are warranteed for 80,000 miles.

2001NBMZ28

Forgot to mention earlier, leave the code stored so the dealer can see it.

RPM WS6

iTrader: (3)

I guess I've been lucky then. (knocking on wood)

I've had over 10 GM cars that came stock with cats ranging in age from 1976 to 2004 and I can't ever recall one loosing a stock cat before at least 80K miles. Some had well over 100K on the stock cats. I've got a '76 Eldorado with the stock cat (They were HUGE back then) and 120K miles of use. I hope my luck holds out.

Monguse01TA

Thanks for the advise guys! AND.. for the warranty info. I would never have known that it was under warranty to 80,000 miles. I'll make the call to the dealer on Monday. Thanks again!