What is supposed to keep the cat heat shield from rattling on the 93-94 exhaust? I'm able to move it by hand, but I think all four fasteners are intact. It doesn't seem to attach to anything on the exhaust. Is there a pad or something that should be on the inside?
93-94 Cat Heat Shield Rattle
- Thread starter Roldan
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No experience with this directly on my cruiser but on other cars I have seen these shields are just a hair smaller than the converters (there will be a small gap between the parts when lined up but not bolted) and when you tighten up the bolts it pull the two together tight enough to keep it from rattling. Over time the metal can and will stretch (all those hot/cold cycles take its toll) and could become loose. You can kind of see in the image you posted there may be some metal bands on the inside that act like a spring to achieve this.
You could try replacing it or take the shield off and see if you can bend it or those bands in such a way that it will clamp tight again. You could also try getting some catalytic converter heat wrap (They make stuff specific for this not normal header or exhaust wrap due to the heat), wrap it up and put the shield back on. The wrap should fill the gaps again and keep it from rattling. The wrap will also help even more with heat transfer to the cab too.
You could try replacing it or take the shield off and see if you can bend it or those bands in such a way that it will clamp tight again. You could also try getting some catalytic converter heat wrap (They make stuff specific for this not normal header or exhaust wrap due to the heat), wrap it up and put the shield back on. The wrap should fill the gaps again and keep it from rattling. The wrap will also help even more with heat transfer to the cab too.
There is a “spring” sort of piece that’s part of the shield. When the shield is bolted on this spring bar compresses. Over time the heat cycles take the spring out if the spring. I removed my heat shield a couple years ago and haven’t started any fires yet. The heat shield itself gets very hot anyway.
You could remove the shield and stuff some fire proof material between it and converters but you will probably twist off a stud or two while disassembling the clam shell.
You could remove the shield and stuff some fire proof material between it and converters but you will probably twist off a stud or two while disassembling the clam shell.
- Thread starter
- #4
Thanks for the suggestions. Now I see a spring in pictures of the lower shield 18434-66010. I will attempt to rivet in a new spring as I'm not able to locate header specific wrap. I may also try removing the lower cover and fastening the upper cover with the steel bands used to secure header wrap.
Did you have to remove the cats to get the heat shield out?
I decided to delete that heat shield while te entire exhaust system was out for a refresh so I can’t accurately comment on your question.
I was able to rip it out with some vise grips with the cat in place
I likely will do that because I have an exhaust leak from one of my cats. Only problem is all the nuts are hopelessly rusted on :/
The easiest thing to do is drop the whole exhaust system, First jack up the truck and support it on jack stands, next disconnect both O2 sensors, then disconnect the exhaust where the head pipes connect to the exhaust manifolds, Next place a floor jack under the exhaust system to support it's weight,
Then disconnect the hanger clamp on the exhaust pipes in the engine bay on the passengers side firewall, Last unbolt the exit side of the cats from the Y pipe, and lower the whole exhaust system out of the truck ,
Once out of the truck it will be easy to cut off the rusted bolts holding the cats in place,
Oh one last thing, DON'T sell, or throw away the old factory cats, Who knows, when the time comes to sell your truck, the new owner just may want them, Or you may move to a state where emissions testing is required, in that case you'll need to reinstall them,
The last time i did this job these were the Toyota factory part numbers for the different gaskets you'll need to put everything back together
90080-43036 for head pipe to exhaust manifold gasket, cost as of 6-23-2023 $10,89 each, Toyota's parts book list this as "gasket exhaust pipe"
17451-52060 cat inlet gasket, cost as of 6-23-2023 $7,79 each, Toyota's parts book list this as "gasket exhaust pipe"
90917-06076 cat outlet gasket, cost as of 6-23-2023 $14,31 each, Toyota's parts book list this as "gasket catalytic converter"
You'll need 2 of each of these part numbers in order to complete this job,
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Why are you looking to remove the heat shields?
Extra room to install sliders and I have a really bad exhaust leak on one of my cats.
These are known to generate tons of heat on the passenger floor anyway and removing the heat shield would make that even worse.
I have white knuckle sliders on mine and I did not need to remove heat shields.
