Originally posted by djcontra
Oh well, if I have to, I'll install one of these for the o2 sensor
I'll just hope X-pipe's give the same gains on v6's as they do on v8's
Since when are you running a V6??
Seriously, the OBD-2 system actually runs 4 O2 sensors (2 pre-cat, 2 post-cat), not 2. OBD-I has just one O2 sensor, and you *could* get away with running it on just one side, but here's what I'd suggest doing.
Rather than running an X-pipe, why not build just a pure H-pipe instead, and running the O2 sensor in there? When I built the exhaust for my racecar, I had a bung welded into the cross piece of the H-pipe, and I run it that way. Otherwise it's clear 2.5 inch pipe all the way back (I don't run any cats or mufflers on the racecar).
So you could have a true, dual exhaust, and still run a single O2 sensor (which OBD-I will require).