Most likely a very stupid question...


No!! It's NOT A Monte!!!
Jan 14, 2002
Ok, well I'm getting a new cat-back exhaust system done in 2 months, my brother bought me 2 muffs and a cat for christmas and I'm bringing the car to a local shop where they will do the piping/installation..but I just now realized this..
He bought me a 2.5'' cat..and I plan on getting a 2.5'' exhaust system..BUT I have a 3'' downpipe.. since I have a 3'' DP does that mean I need a 3'' cat??
I hope the answer is no...but it prolly is yes..
You could run the 2.5", but it will be a BIG restiction. You should have 3" everything (downpipe, pipes, mufflers, cat).
Welp, you can always run the CAT for inspection, etc., then simply replace it with a 3" test pipe, until the next inspection. I'm figuring there's prolly someone out there that does just that.:rolleyes:
The Cat to Cat-back connection is the same size on 2 1/2" and 3" CATs.
I'd be willing to guess there are a TON of TR owners using a 3" d/pipe w/ a 2.5" exhaust system. The restriction would come from the cat convertor...unless of course you gut it.:)
The inlet on the cat. needs to be 3" or some sort of adapter can be used. Or I believe Keith Mease can open up the inlet to the cat. to make it 3". Forgot what he said he charges for this service. Maybe your shop could open it up also.
For likely the same or less money you could order a mandrel bent Hooker 2 1/2" exhaust (~$280 from Jeg's or Summit.) It'll out flow any muffler shop 2 1/2" job (they simply can't avoid putting kinks aka: RESTRICTIONS at the bends!) & it is a high quality piece.

Save the cat for emissions testing & just run a test pipe w/cut out the rest of the year. :)

Doug C.
Ok, well as long as it can be done then it's fine..
The test pipe will come later, If I get it..
The 2 mufflers are Hooker Super Competition muffs and the exhaust should be on the stock position ( should I have to tell them beforehand?)
Actually the Hooker system comes with a very good flowing straight through design muffler (Aerochambers) as part of the kit. There used to be a couple of vendors who would sell it to ya without the mufflers, so may want to look into that. One thing to consider though, IF I remember correctly the Super Comp mufflers are a chambered design kinda like the Flowmasters & on a turbo car this = RESTRICTION! Oh BTW, the Hooker system's tailpipe exits just behind the rear fenderwell like the stock setup.

Also, check with Jack Cotton and Torque Tech as they both offer some quality exhaust systems. I know as of a couple of months ago TT would still sell ya a kit without the mufflers.

Just take the kit to any GOOD local muffler shop & they should install it for around 50~75 bucks ORRrrr takes a couple of hours in the driveway or garage & a buddy to help hold stuff in place. :)

Doug C.