I've had my RP supercat on for 2 years now, its always smelled like a boat, really strong exhaust smell so i knew i was screwed. when im getting it done the guys eyes are watering he kept asking if i had a cat on or not. The max number you can get is 35 for unburned fuel mine was 980 at 15mph and 880 at 28, i barley passed the o2 by 20 or so in each 15 and 25. going to swap out my old stock midpipe and reflash jeff's map off for a day or 2 and try again. i'll update on if a old cat sitting under a tree still works -_- but i do have a good friend that maybe i could swap cars with ehehhehe its looks the same but i dono. i'll update.

 

don't they scan the Vehicle info off the inside of the door?
your RP is probably blown out, it should have performed much better then that. Throw the OEM cat on there and re-test, you should be good to go.

when you have the RP off, take a peak inside, I get the feeling the honeycomb material is broken

 

i was wondering, did you pass before, with the rp supercat on?

 

Id be curious of this myself....I was looking to pick on up to solve my blown cat problem....no passing would probably be a big deal lol .....

 

Swapped the old stock Cat back on FYI ( it was under a tree rained on not covered not anything just on dirt.) drove 20 miles smelt like new exhaust install smell, but just holding my hand behind the exhaust comming out smelt beautiful compaired to RP lol. Retest and for unburned fuel nothing came up, as for the 02 like 20 and 54 out of possilbe 700-800 so that stock cat is heavy for a reason..... it works. gonna keep it on for 1 tank fill up see MPG numbers.

As far as the RP supercat its not so super for longevity but 20k miles i'll take it.... i had been hearing marbles in a can noise when i touch the accelerator any time, when i pulled it off i gave it a little giggle and ya the honey comb stuff is clinking around in there.
So options..... thinking of trying to get that honeycomb **** out of there but its pretty solid, or cutting the highflo cat off and just replacing that section with the 3.5 inch pipe. All i know is i hate my car sound right now, its quiet umm quiet and o yeah its quiet -_- dont get nice backfires when its warming up with the Vac on. but far as sound and O2 sensor goes will there be any issues replacing that section?