Need to change my stock cats was wondering what are some good highflow cats that wont throw a cel and should i upgrade the y pipe too??

 

My Z1 cats have thrown a code twice since ownership earlier this year. Cleared with a standard OBDII scanner. Nevertheless, they are quite raspy as they are 100cel cats. Fast Intentions and Berk are both I believe 300 cell cats and have a much lower chance of throwing a code.

 

Whatever you end up getting, if you do throw a code, you can always have the O2 sensor mounts extended. That's what the test pipe companies do, although I'm not 100% sure that it's a surefire fix or not.

 

I have the Z1 as well and they finally threw a code as of a week ago after about 8 months of driving with them, they are raspy as well but they are a cheaper option.

 

Coming up on seven years and 30k miles on a pair of Fast Intentions resonated high-flow cats. No O2 sensor CEL ever.

300 cell-count catalyst and a resonator... they purr (and growl) in a way that I never get tired of.

 

I assume you still get that hiss when rpms fall tho right? Never heard hfc not leading to that noise. From a performance POV, do you really think the 300 cell actually did all that much? I’m legit asking, not being snide. Oem are 400 I think.

 

If you listen for it, yep, there's a quick hiss on deceleration when you release the throttle. TBH, I haven't thought about that in years. But yes, that's a thing.

Re. Performance... for that first year, I had the FI cats feeding the OEM catback, and absolutely there was a noticable increase in power. Not dramatic, noticeable nonetheless.