mtinkle

iTrader: (4)

Recently my passenger side cat took a dump and broke internally making a horrible sound. Took it to the local Pontiac dealership, fixed it at no cost (thank god) and informed me that my car's covered for 120,000 miles through GM. Anyways... i'd had a SES light for a long time and just figured it to be that O2 or the cat since that's what autozone's scan told me. But after the cat replacement the codes gone, problem solved.
So my real question is would that code have effected my performance that much? I guess with my cat broken the exhaust wouldn't flow very well through that side... but am i going to notice that much of a difference?
Thanks!

DVS99TRANS

iTrader: (7)

It would most likely effect the performance for that side of the motor the cat went bad on. I know if it was the pre-cat O2, I know it will pull timing, but not 100% sure if it will do it for a rear O2.

rnl35thss

iTrader: (14)

Sometimes when the catalyst comes loose it can restrict the exhaust if it turns just right, but you normally don't have to wonder if something is wrong it runs like a dog when restricted.

mtinkle

iTrader: (4)

the before and after performance isn't night and day, of course in my head i think it's better, but mainly i was wondering if timing is involved any on the cat/rear o2 code?

WS6addiction

iTrader: (1)

The codes themselves (P0420/P0430) don't effect engine performance at all. It's just your cars way of saying "Hey, there's something wrong with my cat."

B-Unit01WS6

He's right. The only problem you would have is possible exhaust restriction. All your rear o2's are there for is monitoring your cat efficiency.