code p0420 catylist efficiency low bank one
is it cat or the o2 sensor didnt lookinto it yet code came one today braught it to my shop and im gonna look at it tomarrow but have you had any experiance with this or weich problem it is?

 

Could be either one. If you're under 80k miles I'd take it to a stealership and get your cat replaced for free under federal warranty. If it still does it after that, throw in a new o2.

 

Bank one is the left side. That code is usually for the o2 sensor, not the cat. Again that is in most cases I have seen.

 

I am going to disagree with you....in my experience at the dealership a P0420 is 100% a cat failure. I've replaced several for that code on the f-bodies....mostly the P0420 for drivers side, but I have had a few P0430 for the passenger side. GM also released a special policy for the 00-02 f-bodies that extends the warranty from 8yr/80k to 10yr/120k.

WS SIKZ,

If you fall under the 8yr/80k, take it to the dealership and tell them you think it's a cat problem. They will diagnose it, verifiy its the cat, and order you one. Hell if its a pontiac dealership they may have one in stock.

-Josh

 

I also got a P0420 and a P0430 code. If i take it to the dealership to be replaced and they scan it, do they charge you for the scan?

 

P0420 is a bad driver's side cat. I had this code right after I got the car last Summer before the LT install. Went to the dealer, they scanned it and replaced the drivers side cat. Absolutely no charge.

 

ok thanks

 

Friend of mine had his drivers side replaced free under warranty - no charge for the scan if they diagnose the cat(s) as the problem. He didn't clear the code - left the SES on.

 

I thouhgt code P0420 was for smoking too much bud in your car and getting it all smogged up.

 

So they charge if they scan it and its not the cats?

 

If its not the cat they will charge for diagnosis. Like I said, EVERY f-body that has come in to the dealership I work at with the P0420 has turned out to be a drivers side cat.

 

I just got this code last night coming home from work.

 

+1
Same for me Drivers side. my car had about 30K miles at that time too.