I was able to get the car on a drive-on lift today and had one of the shop guys operate the throttle while I looked under the car. It's been buzzing a lot and it seems to be coming from the cat. It is either buzzing against the heat shield or something in the cat itself is loose.

Does someone have a mid-section or test pipe FS or that I could borrow, or know where I would be able to get one? I'd really rather not have to do any welding. I'm thinking about unbolting the mid section and just trying to hollow out the cat. Because I'm an active duty military member living outside my state of residence, I don't have to get the car inspected, so I could just straight pipe it but I don't want it to be loud and smelly.

Ideas anyone?

 

is it just buzzing itself? or hitting something?

 

I think it is just buzzing on its own. I tried putting pressure on it with my flashlight but it didn't seem to make any difference at all.

post 2k!

 

prob the element inside the cat deteriorated and a piece is just rattling inside the cat. test pipe time

or unbolt it and see if it shakes out.

 

I wish test pipes weren't so expensive. I'll probably just gut it or buy another identical section from DC Auto and see if that piece rattles.

Other thing I'm trying to figure out is engine mounts...I bought "OEM" I think either Meyle or Mahle engine mounts awhile ago for about $75 apiece but they are totally collapse and the engine shakes as bad as ever. Do I go $400 for a pair of Porsche mounts or about $300 for lindsey or pelican parts aftermarket mounts? They now offer ones with dampers instead of just solid mounts but I haven't heard of anyone using them.

 

test pipes aren't expensive....it's just the "custom" flange parts and jig welded pieces.

i made mine with a cherrybomb glasspack from autozone and 2 three-bolt flanges.

 

hmm....my car must be a wierd one...cause my exhaust system didn't have the extra pipe #24. in fact..I had to weld an extra o2 sensor bung in that location. where does that pipe go?

 

my cat internals were shot too so i upgraded. you could just cut out the cat and put a straight pipe in with clamps to seal it.

 

could just be a loose chamber in the muffler. Does it buzz at idle? certain rpms?

 

mine is missing that pipe too, AND i have the annoying rattle...

 

I have a 64k cat I might be willing to part with if you want to go that way.

 

Guys, part number 24 is an old piece of emissions testing gear that no longer serves an purpose. Most of yours were removed or rusted off.

Colin, you think it would be a pain to ship? There's something to be said for bolting in. Let me investigate more and get back to you.

It sounds fine at idle, but it buzzes at 3k rpms and about 5k rpms. Worse when under load. When you're actually driving it sounds like a ricer fart can when you shift.