Hey y'all. Okay I'm a total noob to this exhaust stuff. I want to get a Flowmaster, but I want to make 100% sure I'm getting the right size intake/outgo before I buy. The guys at my local Nissan stealership are being schmucks and not returning my calls. I've been underneath and done my own measurement, but I just wanna make sure. So... am I right:

intake = 2.5"
outgo = 2.5"

Any insight you pros have would be great. Thanks!

I think its actually 2.25"

I know the piping is 2.25. Unless the piping narrows after the muffler, the muffler should also be 2.25.

I remember having my piping widened to 2.5.

+1

my piping is 2.25

ID vs OD probably.

inner vs outer diameter in layman's terms

hey rift... I put a flowmaster series 50 dual inlet and outlets on my '02 sc and went with 2 1/2" piping and it worked out great and sounds like somebody stuffed a v-8 under the hood...check out summit racing or flowmasters site for more info.good luck

Hey thanks for the heads-up on this. I checked around the Flowmaster site, and I can't find anything about fitment for Xterras. Did you go with 2.5" for the whole exhaust (in and out of the muffler)? So far you're the only one who's suggested 2.5" . I wonder if the S/C uses larger piping....? But I'll be sure to check out Summit. Thanks!

I did 2.5 from the cat back with a Flowmaster 40 and love it. Before this I had the Stillen exhaust and it was great until it rusted out. I didn't really feel any difference between the two, but they are both better than stock.