Catalytic converter warranty

Kursk · October 9, 2005

I'm fairly convinced my catalytic converter (at least one of the two) is on its way out. It has that characteristic vibration at certain rpm, same vibration is evident when I basically touch it, much less hit it with just a hand.

My dealer is convinced it's working fine, since they had it tested and it works. Never mind the rattling noise, they say. The same dealer says it's still under warranty (8 yr, 80,000 miles, and I am below both of those) but they won't replace it until tests show it's not working.

Any suggestions on how to encourage the replacement, so to speak? Some mechanics told me that rattling and vibration is a sure sign that catalytic converter is going on.

Thanks.

(99 Silverado 1500, 4.3L V6)

mcreyaufmiller · October 9, 2005

go to a different dealer or call your area GM represenative and tell him your dealer refuses to replace the cat. You should not have to deal with rattling sounds from a bad cat.

Kursk · October 10, 2005

Thanks.

Just curious, what's an "area GM representative"? Not that I want to make a big deal of it, those guys have been treating me nice over other things, just stubborn with this catalytic converter.

If it's under warranty, it's not like it comes out of the dealer pocket, right? And, btw, does warranty cover the cat only, not including the labor? If so, can a person get a new cat and do replacement himself (meaning will they let you do it, I don't mean can I do it)?

bronyaur · October 10, 2005

I just had the cats replaced under warranty on my 99 K1500 truck (obs). The warranty covers parts and labor, EXCEPT O2 sensors. My truck has 2 cats and 4 O2 sensors. Two of the O2 sensors broke when they took them out, and I had to pay for two new ones. They told me this going in, and I've broken them before getting them out, so I just figured whether I did it or they did it they still would have broken, so I saved the cost of the cats. The only difference is GM O2 sensors cost a fortune ($150 each). The aftermarkets are half the price. For what it's worth, my cats weren't rattling, but one of the O2 sensors set a P0430 code which is why the dealer replaced them without question. And on my truck, the header pipes connect the two cats together and the OEM replacement is one giant part. So, I ended up with two new cats, two old O2 sensors, and two new O2 sensors. It cost me about $300.

No, they won't provide you the part under warranty and allow you to do the work yourself. Labor is where they make their money, plus I believe the dealer install is required by the GM warranty.

Kursk · October 10, 2005

Same thing on my, both cats have to be replaced since it's one part.

So, they told you they would break the censors before they went in? Both of my 02 censor have been replaced about a month ago by my dealer, so I would hope they won't break them (the dealer said that censors were making that rattling noise, not the cat, so I had them replace it, it was a part of the deal when I bought this truck used, so I didn't have to pay for that).

My codes were for O2 censors themselves, not for the cat, thus they got new 02's but no-go on the catalytic converter. Actually ran the test, the thing is doing its job, just rattles. "Minor inconvenience" I think that's what they called it, as in not affecting the performance.

GM-Tech · October 10, 2005

So, they told you they would break the censors before they went in?

After 70-80,000 miles, the O2 sensors are often seized in the pipe. Sometimes they just won't unscrew, other times the threads are damaged beyond any further use if you can get 'em out. I'm sure that's what he meant when he said the O2's might break.

When we replace a cat under the 8/80 warranty, whatever is needed to replace it is included, and that includes O2's that won't come out.

bronyaur · October 10, 2005

So, they told you they would break the censors before they went in?

After 70-80,000 miles, the O2 sensors are often seized in the pipe. Sometimes they just won't unscrew, other times the threads are damaged beyond any further use if you can get 'em out. I'm sure that's what he meant when he said the O2's might break.

When we replace a cat under the 8/80 warranty, whatever is needed to replace it is included, and that includes O2's that won't come out.

<{POST_SNAPBACK}>

Yes, that's what they meant. I've had to remove O2 sensors that have been frozen in the pipe and I know they usually come out unusable, so when they told me that it was no surprise. I'm surprised to hear the O2 sensors should have been covered under the warranty install. I thought they should have been, but I figured the dealer knew more about it than me.

Kursk · October 10, 2005

Thank you, Tech and bronyar.

If I may, GM-Tech, ask you this (I assume you work at a dealership.) Would you guys not replace the cat under warranty if it still performed, just made rattling noise?

In other words, what are the qualifications for a warranty replacement? Trouble codes, emission test failure but NOT the noise?

GM-Tech · October 10, 2005

If I may, GM-Tech, ask you this (I assume you work at a dealership.) Would you guys not replace the cat under warranty if it still performed, just made rattling noise?

We would replace it under the 8/80 if the only problem with it was a rattling noise.

I have seen nothing in writing in GM's policy and procedures that says the 8/80 warranty on the PCM/Catalytic Converter is only for when they fail in a way that causes an emission problem. One would think that would be the case, but we replace them all the time for rattles.

I ran a somewhat similar scenario past our AVM (factory rep) just a week or two ago. The truck had 65,000 miles and was in for an exhaust noise. Seems the flange on the pipe, where it makes contact with the exhaust manifold, had cracked and exhaust was leaking there.

So my question to him was, is this covered? In order to repair this, I have to replace the complete cross-over, which includes the catalytic converters. Technically, there's nothing wrong with the converters. They are performing as designed, no rattles, etc. It's just that the pipe they're attached to has cracked and there's no way to replace the pipe without replacing the converters too. It's all one assembly.

He said replace it and we did... under the 8/80 warranty.