My catalytic converter hits my drive-shaft sometimes and makes a loud bang bang bang sound. I tried to cut some of the cat a little where is touches, but it still manages to hit sometimes. Why would this happen. Could a bad trans or engine mount cause this? How about the rubber mounts the drive-shaft goes through, they seemed ok. Any help is appreciated.

 

The carrier bearing rubber mounts allow the drive shaft a lot of movement. I've never taken a close look at the rubber around these bearings on my Evo but on DSM's there are some holes in the rubber - I guess to make them even more flexible. DSMer's would shoot these holes full of RTV to stiffen the bearing mounts when they had the drive shaft hitting things underneath.

 

U need either an Indoor Cat, or a skinnier Cat that's more alert when it's sleeping under your car, damn thing could get squished! Lol

Is this car stock? Aftermarket anything? Need more info. You sure its not your downpipe? For the love of God, don't get under your car and start grinding stuff! We can help you fix it without too much grinding at all!

 

I had the same problem when I had purchased a Vishnu Exhaust for my Evo 8. The quick fix was to take the cat off and take a hammer to it. Make sure that you just bang enough of the cat to clear the driveshaft...don't go too crazy though. I didn't have a problem since.

 

Are you sure its the cat and not the bracket that supports the wiring?

 

I have a megan racing downpipe that has a flex pipe, highflow cat, buchur cat back.

 

Yes it's deff the cat. I can see the scrapes where it was hitting.

 

I have to agree it's the bushings.. Might want to get it in the air and check it all out.. Got any pictures?

 

I agree with this entirely!

 

Could a bad transmission or engine mount cause it to move too much.