SES Code p0430

mxzeatr · December 13, 2006

Hello,

I just recently purchased a 99 ext cab sb z71 with a 5.3L. The truck has 138k on it, but runs and drives perfectly. The day after I bought it I got a SES light, so I took it to my mechanic and he said that Bank 2 Sesor 1 was not functioning. So I replaced the two 02's before the cats...The SES went away, and came back a few days later with a p0430 code. I have read some things, and heard some things that maybe the rear 02's aren't fuctioning properly...I just replaced those last night, and have not driven the truck or had the SES codes cleared yet...Could it really be a bad cat? I have never heard of this before....Also if it is a bad cat, can I get general replacement cat? Or should I get an OEM replacement...I'm a college student so I don't really have the 300+ to throw a cat into this thing...Any help would be appreceated! Thanks

Eric

GM-Tech · December 13, 2006

Unfortunately, you have a bad catalytic converter. Nothing else would cause that code. It's just worn out and won't affect the way the vehicle runs, but emissions are high.

I don't have any experience with aftermarket cats so couldn't say whether or not they'd do the job and get the light to stay out. They'd probably be okay, but that's just a guess.

yeehaw87 · December 14, 2006

Drive your truck for a few miles before you go and buy a new cat. It takes a few cycles to get the code to clear if you dont have a tool to clear the code. My friend had a 200 Silverado with a 5.3 and had his cat go out too. Instead of buying a new one, he cut it open, ripped out the insides, welded it back up and put O2 simulators back on. He hasn't had a check engine light yet. Plus, simulators are only about 40 bucks a piece. I would try putting those on first.

95Sierra2500 · December 14, 2006

I would not recommend 'universal' replacement cats. They are usually garbage and don't hold up like an OEM or direct-fit cat would. If you have any doubt, take it to an exhaust shop and have them get you the right size.

squissh · February 20, 2007

helllo all.

just took my 01 z71 in for the same code p0430. they said my cats are bad and are replacing them. thank god for the federal emission warranty 8yr /80,000 mile.