I have a greddy evo 2 and want to run HF cats or just delete them altogether. Any recommendations as far as sound, not sure if they will drone; obviously don't want droning. I want an increase in sound and slight performance...will it pass smog with HF cats? any recommendations on good brands...

 

It "should" pass smog with HF cats. I would stay away from cat delete pipes unless you are going with a TT kit. The rasp is just nasty.

 

fast intention and crawford cats are the only ones i would recommend.

and imo, if HFCs pass smog then you wasted your money.

even if my cats pass the sniffer, which i hope they dont, they wouldnt pass the visual. so imma just switch em out for the stock ones when the time comes.

 

im running high flow cats with my evo 2. I wouldnt do it any other way. sounds great.

 

I don't understand what you were trying to say here. If your not worried about emissions, why even have cats, go with test pipes, and HFCs will pass emissions and a visual. There are very few people that perform the visual inspection that actually know what they are looking for. And if they see the cats at all they would pass.

Why would you buy HFCs and hope they don't pass emissions? That would be a waste of money.

 

Because if he passed smog, that means those "Hi-flow cats" arent exactly too "Hi-Flowy" . Why not jus remove em when u go in for inspection and put em back on when your done?

 

Sorry, but that is a load of CRAP. N/A cars need some back pressure to perform well down low. HFCs give you more flow than the stockers while not sacrificing all your torque that the test pipes do. If you'd like to run your car at 5K to 6.5K all day then you might be happy with the free HP that the test pipes come with, but for 95% of drivers, HFCs provide a good compromise and still maintain emissions compliance.

I still say, if you didn't want to pass emissions after getting HFCs then you are spending your money wastefully when all you really want is test pipes. Send me $400 and I'll send you two test pipes guaranteed not to pass emissions. LOL.

 

cause i dont like rasp...................

nor the smell of unburnt gas.........

nor do i want to throw a CEL and/or bother with non-foulers

 

Well, those are all good reasons for HFCs along with a slight increase in performance, but you are going to be mighty disappointed when/if you go get emissions tested and find out that your new HFCs pass with flying colors.

 

will you pay for my smog tests when i fail?

 

Sure, send me the bill and I'll get that check in the mail.

 

I'm not sure who thought I didn't want them to pass smog. I want the HF's to pass, so I don't have to put the stockers back on. I put the "..." just because I always do, maybe it threw people off. thanks for the info guys.

 

lol

too bad i dont need to get smogged for a few years

 

Ok all -

1 - smog test requirements and tests are different across the country

2 - With the exception of Crawford CATS, most do not have heat shields and have NO chance of passing a visual, unless they just don't check it.

3 - HFC's will average about 7-9HP and about 6TQ - TP's will get about 2-3 more HP and 1-2 more TQ.

4 - The ability for a high flow CAT to pass a sniff test does not mean it is a bad or low performing CAT - it's just efficient. The gases can still get hot enough to burn of the bad stuff, but still flow well.

5 - Considering HFC's and TP's are designed for off road use, so no smog tests are even there to worry about, you should know what your up against, and just live with the fact that they will need to be swapped out every few years to pass the test.

6 - If you are looking for every HP you can, and also want more sound, then either options is a great one, only to compliment the rest of a complete exhaust system. If you just add the CATS, and stay stock otherwise, gains will be there, but far less noticeable.

Rick

 

nice review, great info...