allright so the first time i measured my various exhaust components, i came up with my downpipe being 3 inches...so obviously i ordered a 3inch hi-flow cat....well i got it not long ago, and after looking at it, then looking at the car, and measuring....i dont think the DP is 3inches, im thinking its 2.5. so i cant really return the cat so i have to make what i have work.


if i go ahead as planned this is the setup i will be having someone install for me.

2.5>3 inch reducer from DP to cat, 3>2.5 reducer from cat to short section of pipe with 02 sensor fitting, 2.5>2.25 reducer to glasspack, glasspack to stock piping.

do you think this would open things up too much? or actually make it flow less?

i think that would work....why the Glasspack tho?

well the stock res wouldve been almost too long if the cat were the right size, immediately after the res, the pipe takes a sharp turn, so if i have to add the extra reducer, the res will definetely have to go...i could move it back farther, but then there would have to be some "custom" pipe bending to get everything to hook back up, with a glasspack of appropriate length, the worst that would be necessary is a short piece of straight pipe...and a glasspack is much cheaper than a resonator, and also theres no flow restriction on a glasspack, and there has to be some on a resonator, because they work off noise cancellation, bouncing the sound waves into each other.