I'm planning on putting a hi flow cat on my exhaust and I was wondering if I should change the donut from the header to the cat or if the old one will be fine. Also should I buy the special o2 sensor socket to take it off properly without damaging it, or would it be fine with a wrench or other tool, Thanks.

alright I guess that means using the old donut is fine according to the responses I got....[X(]

I've reused the donut every time i've taken off my downpipe. I would advise you to get an o2 sensor hex socket. I was just at autozone today and noticed that their free-loan-a-tool program includes these sockets.

Well sometimes when you take the exhaust apart they will come out OK, but you may as well replace it anyway in case it crumbles coming out or something like that. Then you have less worry of leaks too. The donut can't be more than a couple bucks anyhoo.

EDIT: as for the 02 sensor tool, for the price, buy it. It will save headaches of rounding off the 02 itself.

I put in a header like 8 months ago and it came with a new donut, so It's probably still good I'm guessing. I'll try it see what happens.....

I would buy the tool but I don't know how many times I would use it... Aren't they expensive? I'll check out the loan a tool deal, thanks for the input guys :)

well its best to go buy a new donut.... if ya dont need it well keep it in the toolbox.... because if it crumbles when ya pull yours off you gotta wait longer to go buy a new one. ;) they are pretty cheap!

http://www.sears.com/shc/s/p_10153_12605_00996413000P?vName=Tools&cName=Mecha nicsTools&sName=Automotive%20Specialty%20Tools&psi d=FROOGLE01&sid=IDx20070921x00003a


The tool is hardly expensive at all. That's the exact one I have and it works great.

oh wow, for some reason I thought they were expensive[8D]

Are all donut's universal?