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Last week I noticed a metallic rattling coming from under my car during accelerations at about 80% engine load. I had to take it in for an oil change anyway, so I asked the dealer to take a look.

Turns out the heat shield over the catalytic converter had rusted through 3 of the 4 bolts. They pulled it off an we ordered a new one. When they tried to put it on, they claimed they couldn't get the bolts off because of the rust and corrosion. They told me I could pay $1700 dollars for a whole new converter or I could just go without it. The service guy told me he didn't think it would be a problem to just leave it off.

I'll hit the quarter million mile mark in the next few months, and I'm hoping she'll go another quarter million. :)

So, do I really need the shield? Any other options?

The shield serves a few different purposes:


Protecting other items near by that are not very heat resistant (plastic? Wire sheathing?)
Protecting the cat from road debris
Helping keep the cat at a higher, more stable temperature


Sure, you can drive without it but you're better off with one. You might try soaking down those rusted bolts really well with a penetrating oil, then applying a bit of directed heat (hand held torch?) at them to break 'em loose. Worst case scenario, drill some holes through the bolt heads and wire-tie the shield in place -- much cheaper than $1700!!!

Yeah, I was thinking the wire tie route as well, but you probably want that shield there, for sure. Or drill out the bolts if you can and put in new ones.

....

So, do I really need the shield? Any other options?

That's one of those parts I don't replace when a vehicle is nearing the end of its service life. If you are serious about getting another quarter million miles instead of starting down the path to jalopy-dom you should replace the part. I would guess that there are many local shops that can handle the job for a lot less than $1700.

Like others have said, put the new one on by other means, try to soak the rusted bolts or, wrap and tie it with stainless steel wire. I would make sure and have some kind of shield on it. The small air gap between the cat and the shield gets rid of a lot of degrees of temp.

umm..the converter gets EXTREMELY HOT! Do NOT remove the shield unless you like a well toasted interior..or if you only drive on short (<5mi) trips EVERY time.

Depending on the location it may prevent a grass fire if you park in the wrong place. $1700 sounds like a lot of money, is there something special about the cat in an Insight?. if there are no emission testing in your state get rid of the cat.

well, depends on whether you want any possible fires.... if you don't have any leaks (like oil) then it's not as bad. had a coworker who didn't put the heatshield back on and his car started on fire at a stop sign on base. that was one hot car. but i will add, he had some oil that had leaked and some of it was in the exhaust tunnel. which, once hot enough, BURN BABY BURN!!!!

I had the same shield issue on both my GLC and my Civic. My mechanic said it might only be a problem if I parked over a pile of dry leaves. We just left it off of both cars and went on motoring for many more thousands of miles. It sure beat listening to the annoying rattling and buzzing !