High Flow Catalytic Converter

[F22-GURU]

Yeah.... Most so called hi-flow cats on ebay are really just test pipes.

..and not to mention Illegal !!

[lonski]

So our cars are 15+ years old. Will emissions test tell you if its time to replace your cat?

[deevergote]

So our cars are 15+ years old. Will emissions test tell you if its time to replace your cat?

If you fail, yes... that'd be a good place to start. There are a number of things that could control the emissions, though. The cat isn't everything. The o2 sensor, the EGR system... even your ignition and valve timing (that ensure a proper burn). Also, most modifications, especially to anything before the exhaust, will change the way the ECU reacts. More air means more fuel from the ECU... which often results in a rich condition (after my P28 was tuned, I gained about 5mpg, and my bumper is MUCH cleaner!)


Anyway, most "high flow" cats are garbage. I've heard good things about Metal Cat, Magnaflow, and... well... supposedly Vibrant has gotten lucky with some of their designs and makes good stuff... I wouldn't put them among the best, though. SMSP also makes a good high-flow cat, though I believe they may be ceramic like the one JesseXC pictured. SMSP is small-time, but they're very well known for making some of the very best headers out there (their H22 header has always been one of my dream parts!)


The way the Honda catalytic converter is designed, it's not overly restrictive. Of course, it WILL provide some restriction, but I'd rather lose a few horsepower than I'm not going to feel, than destroy the environment, break the law, and have my car smell terrible. I have a friend that throws his test pipe on when he goes to the track, and then puts the cat back on the next day. If you swap it regularly, the bolts aren't hard to get off. It's a 10 minute switch... easier than an oil change.

[NAiL05]

Those sparks are the inside of the cat coming apart.

If its a test pipe or any type of resonator that would be a false statement. And I would assume since he said high flow cat most likely its an ebay brand thats just a mini resonator since he didnt state a brand or anything.

[JesseXC]

If its a test pipe or any type of resonator that would be a false statement. And I would assume since he said high flow cat most likely its an ebay brand thats just a mini resonator since he didnt state a brand or anything.

True but when did he say he had a test pipe or resonator? I would think he would be smart enough to know the difference between that and a cat.

[NAiL05]

Just sayin thats most likely what he has.