Hfreak

I went from stock cat to TP on my 2006, likely my cat was restrictive but found that the TP woke the car up dramatically. Stock cat is in a box, never bothered to investigate.

zeroptzero

the test pipe works so well because it maintains the constant diameter keeping the velocity of the gasses up and creating more of a resonance, none of the aftermarket cats can do that even though they flow almost as well as a test pipe. I would love to try out a test pipe but I am always the first one to complain when i'm behind one of those stinkers.

Hfreak

I didn't notice a huge difference when I put a Berk HFC on my 2003 to replace the stock cat besides the sound but made a huge difference on my 2006. Maybe I should throw a TP on my 2003 and see how the butt dyno responds?

b_ron

Maybe look into some sort of a single exit?

Jah2000

I have about 110k miles on my MY03, and I am sure a new cat would be very beneficial. But, I'm very curious as to why a Berk HFC would not pass in Cali? (I'm in Cali)

I know, technically, it's intended/specified for "off-road use only" in Cali... but how does a smog shop know, and exactly why would a smog shop reject it?

Would it be the different emissions readings compared to the oem stock cat, or the visual inspection???

Has anyone here successfully passed smog with a Berk HFC in Cali???

I know I can just slap the oem stock cat back on, when smog time comes... but I'd rather be lazy if possible and leave the Berk HFC on (if I had it), and also less junk/storage space taken up in my garage if I didn't need to keep the oem stock cat.

Car Analogy

It would fail the visual inspection. Yoy could fit stock heat shields to it to make it look stock. But if you're caught, the penalty would be high.

Jah2000

Thanks. I'll keep the stock cat in the garage for smog time then (if I end up getting an HFC).

Pinky

That's what I have to do every year!