cjb49er

Seriously considering buying an '02 SS; the current owner says he has SES code 420, bank one light on and can't figure it out. He had the bank one front 02 sensor replaced today and the SES light came back on after 20 miles.
Back flow test showed catalytic converter to be functioning properly. Before I make a decision on this car, anybody have recent experience with this issue? Any idea what else it might be? The car is an '02 with about 38k miles, original cats still on there I believe. Any one know if GM would replace the cats if that turns out to be the problem? If not, anyone replace their cats recently, what kind of money am I looking at to have it done myself?

sicksspeed

iTrader: (2)

Cats I believe are 8 years 80 k miles. The code almost guarantees failure. Eastern cat for economy. Walker exhaust, good or gm best.

joecar

P0420 = bank 1 cat efficiency is degraded...

PCM induces a fueling step and measures the response time of rear O2 relative to front O2, if it's too short then it sets P0420.

joecar

GM's extended F-car cat replacement warranty (120K miles or 10 years) has already expired (about 2 years ago).

cjb49er

thanks guys, I was afraid this would be the case, and expect to have to replace the cats. Any of you have any recent experience with this repair, like what I should expect to pay, ballpark estimate of course?

joecar

At the online GM parts stores, 2002 F-car cats are currently about $370;

you will also need a manifold-cat gasket, a few dollars;

you might need some manifold studs/nuts, a few dollars;

(the cat you should get from GM if you have to pass emissions testing, the gasket/studs/nuts you can get from RockAuto or similar places);

if you have tools it is a fairly easy job;

if you're having it done, it's probably $800-$1000 or so (IDK for sure) just because those cats are normally priced at $600.

cjb49er

thanks joecar, greatly appreciated! If I buy the car and find out it needs the cats, I will grab a couple of friends and have at it ourselves... hate to waste money at a dealership if I don't have to...

01WS6/tamu

iTrader: (37)

Put a set of longtubes and a ORY on it and put the damm cats in the trash can.

01WS6/tamu

iTrader: (37)

Or I have a set of gutted oe cat shells then just get the cat monitor codes turned off.