Re: GMC Sonoma: Whats This?

Oct 12, 2003 4 Replies


Hello guys, just wondering what this tube is on my exhaust. It's between the


>manifold and the cat on the pipe. Could I have 2 cats?

A pre-cat maybe? Maybe a resonator. Also, I'm not the usenet patrol, but please post images and such in Binary newsgroups. Fewer people will see your image if you post it on a non-binaries group, many news servers strip the files. You could also post the image on web space someplace (some ISPs give you some with your account) and post a link...

Likely one of the following:

-That is a pre-catalyst, and you do have two converters

-That is the converter, and what you thought was the converter is actually an exhaust resonator.

Repair manual says the pipe AFTER that tube is the cat. And what's a resonator?

P.S. Sorry about posting that image here.

A resonator is a device that's put in to alter the resonance characteristics of the exhaust system, I believe it allows them to use a less-restrictive muffler to cut exhaust noise.

What year is this truck?

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