So there is a terrible grinding coming from my exhaust, and it sounds like it's coming from the cat. I haven't been under my car to check it out, but i'm pretty sure it's the high flow cat i've got. It only seems to do it right when i start it up and only under ~2,500 rpm. It's really starting to bug me now because it sounds like ****. soo is there any easy fix to this or do i have to get a new one welded in? thanks.

 

get under it and take a look for anything lose,
ill never forget the time my car came loose from the rest of my
golf's exhaust...
that was a fun day.

 

Grinding or croaky? I know mine exactly at 1500rpm sounds croaky as if there is like back pressure being pushed out or something.. IDK!

 

Mine sounds the same also, it sounds like something is rattling around like its loose but Im not quite sure if thats the problem. Right around 2500 and below.

 

Do you have a stock cat? If so the dealership would prob fix it under warranty. Anybody know any fix for this besides replacing the cat?

 

Yeah stock cat. Is that what it is?

 

Yours is prob either the flex pipe or the cat. Either way you can take yours to the dealership and they should fix it.

 

Alright, thanks dude. Its been bugging the hell out of me for the longest time. Ill tell them about it when I get the oil changed.

 

Got underneath and when i wiggle the exhaust it sounds like something is rolling around in the cat. What the hell is in there? Should i just replace it?

 

It's probably the crappy flexpipe that Mitsu used on our stock downpipes. I just took my stock one off the car (put on RRM downpipe) and my flexpipe showed signs of leaking quite a bit.