After-cat H/X pipe

[txminime]

I've search on this but can't find any definite answer.

Have anyone dyno'ed their after-cat H/X pipe and see how it compares with Off-Road X/H pipe? I'm pretty sure off-road pipes will make more power, but I'm curious if the factory cats is really *that* restrictive...

I'm considering adding an Off Road X Pipe before taking the car over to TS for a dyno tune. But even without a CEL, I'm sure the exhaust note and stinky exhaust is enough to make a safety inspector look under the car for cats. I know it's just an hour or so to swap the OEM pipes back, but my experience with Fox/SN-95 exhaust is that eventually I'm going to ends up chasing exhaust leaks and rattles if I keep R&R'ing the pipes and I'm just getting too old for that now...