jason1384

iTrader: (1)

I tested my car and said i need 2 new o2 sensors. Just how important are these? They are like $73 a piece and was wondering if i can hold off on getting them.

Weezzer

The two rears you can chunk, the two fronts you need if you like getting more than ten miles per gallon.

jason1384

iTrader: (1)

How do you know which ones are the front? I got a P0420 and P0430 code.

P0430 Catalyst System Efficiency Below Threshold (Bank 2)

P0420 Catalyst System Efficiency Below Threshold (Bank 1)

sapper_daddy

iTrader: (12)

how many miles and what year is your car. My cats had to be changed last year and I have an 01 with 42K, apparently emissions is warantied for 8 or 9 years and good to 100K along with the PCM. Just a thought, that can be considered emissions to a certain extent. Maybe your cats are bad like mine were it threw P430

jason1384

iTrader: (1)

My car has about 56k miles but I JUST had my car tested for state inspection and I passed, so i dont think it could be the cats otherwise i would have failed the emissions.

jmm98LS1

iTrader: (28)

Those two codes are for the catalytic converters, the rear o2's have sensed that the performance of your cats is below acceptable. You could have just squeaked by emissions testing before your cats were bad enough to throw a code.

pirhana

mine had the po420 code 2 weeks ago at 52k,dealer changed it no problems

jason1384

iTrader: (1)

So i just take it to a GM dealership and they will replace the cat for free?

marv

iTrader: (40)

Tune out the rears...make sure the fronts are good.

How important are they? Try driving with a bad one...haha.

First H/C swap I did, I had a bad front O2 after the install...car barely ran worth a crap. Bucked, jumped, surged...could hardly get it to run at all...