Catalytic Converter

Topic: Catalytic Converter (Read 1151 times) previous topic - next topic

Catalytic Converter

November 13, 2006, 11:07:08 PM

Hey,

Anyone know why a catalytic converter rattles? The '88 Tbird has a catalytic converter ahead of the ler and I have discovered that something inside it is rattling. NO, it's not the shield. I rapped on the exhaust line and the rattle sound is definitely internal to the cat. Does this make sense? Seems like something inside has cut loose. I assume this means I will have to replace it. Plus, it seems like this v6 has 3 of them----one each on the exhaust manifolds and then joined to the center one.

John R

Catalytic Converter

Reply #1 – November 14, 2006, 10:02:29 AM

Yep, the substrate has come loose. It might just rattle around in there for months without doing anything bad, or it could break into chunks and block the rest of the exhaust, or it could get battered around until it's a solid lump, also blocking the exhaust.

Catalytic Converter

Reply #2 – November 14, 2006, 11:06:49 PM

Thanks,

I was afraid someone would say that. I have ordered a new CAT--I hope it comes with the short curved pipe affixed to the front side to a mounting at that end. There is also a welded on mounting bracket arm. Without those in place, I am screwed. Well, there are many shops here that can chuckle if I show up.

Catalytic Converter

Reply #3 – November 15, 2006, 08:54:32 PM

Mine did the same. First the rattle and no power, then spitting out pieces of it out the tail pipes.

Catalytic Converter

Reply #4 – November 18, 2006, 11:19:48 PM

Believe it or not, it was the heat shield. I looked at this last week and knew from my past experience with these that the corners of the shields separate from the screws holding the shield halves tight together. This time the screws were there, but two corners on the same side---one screw on one side broke in two and remained in place--talk about deception. The other was loose but hidden from casual view last week. Anyway--I fixed these and no problem now. I either return the cat I bought or keep it as a reserve part. As far as replacing the cat--looks like the biggest headache would be pulling its support bar out of its molded rubber mount. For now I can pass---whew!

Catalytic Converter

Reply #5 – November 18, 2006, 11:27:52 PM

haha i just found this thread, cant believe no one mentioned that! its very common with converters. most people just yank it off, problem solved.

return that other one! theyre expensive! if you car has good power (as much as you know it should have) then you converter is in good shape and isnt plugged. dont replace it if its not plugged or if its still doing its job right. if you have emissions testing and they test the exhaust fumes with a machine and you still pass dont bother replacing it. when it does wear out, gut it (if emissions inspection is just a visual inspection) or replace that section of the exhaust with just pipe

(if no emissions inspection is done at all)

Catalytic Converter

Reply #6 – November 19, 2006, 08:13:51 PM

Today---took the CAT and bolts back--full refund. I bought ignition parts and the store has treated me well in the past. Glad they did. No point in storing a CAT for a 19 year old vehicle. Got lucky this time especially since the box was marked as a FED EX deal from the southeast. I would really like to think the T-bird will last 30 years--but 30 yrs??