Hey guys, I was just wondering if its been experienced firsthand by any of you, or have seen proof that gutting a cat on an otherwise stock B-series engine hurts horsepower.

the reason i ask is that i had my car baselined a while back, and i put out some pretty low numbers compared to other engines/cars with comparable setups. the only difference was the gutted cat i was using.

i searched, only finding how-to's, environmental arguments and claims that it "helped" but no proof of such gains in hp.

come to think of it, i was still using my stock OBD2b ecu, so the air fuel ratios must have been off, because of the difference (or lack thereof) in the readings between the primary and secondary o2 sensors.


Modified by Spec R at 8:09 PM 3/5/2006

 

It can.By decreasing backpressure the engine can run lean and make less power.The ecu will try and increase fuel with the o2 but it may not be enough.
It usually sounds crappy too.

 

oh yeah, my dyno vids sounded terrible...even more so than the NA guys running without resonators...