I have a 1990 gmc jimmy s-15, and i want to know where is my heat shield or whatever it is that rattles when i am accelerating. it sounds like it is my catalytic converter or something.it only is there when i drive so it is impossible to get under the car without jacking the back tires off the ground. i dont want to do that so if anyone has any suggestions thank you.

hummm.. I had a 2000 Jimmy that I always looking for the heat sheild too... always rattled when started up and driving to about 15 mph.... turns out I just let it go until too late... the noise turned out to be the cadilic convertor inside parts falling apart ... once the muffler guy took it off to replace it I picked it up and shook it and sure enough the rattle was there along with a bunch of metal falling out the ends .... best to just get it replaced... or cut it off and run a straight pipe to the muffler ( don't do that if you have to have vehicle inspected for any reason )

Originally i thought it was my Cat too, but i somehow picked up the heat shield info somewhere. How hard is it for a beginner welder to replace the cat with a new one or a pipe, as well as swap out the muffler possibly. I have welded very little and am worried that i might blow out a hole and then have to take it somewhere to fix the leak later, any advice will help.

On my old 2000 jimmy ( traded in last year ) its not hard to weld a new cat on... kinda easy .. or rather the muffler guy made it look easy :grinyes: ... I would assume its just a hassle to get a bead on the top part of it but its still able to be done..... I don't really recommend it but you can always get the cat and a couple of clamps .. that would get you by until the clamps expanded from heat ...............