Sup, I'm new the forum and I had a question about downpipe and high flow cat..

there is no real difference between a high flow cat, 02 housing and test pipe rite..

I'm looking to buy a high flow cat, that won't cause a check engine light and I will pass emissions if possible.

Any recommondations?

I'm looking into getting the HKS 2.75 downpipe.

Thanks

 

What do you mean "there is no real difference"? Those are all completely different parts. The test pipe and HFC go in the same location, but they are quite different. The O2 housing isn't even part of the exhaust piping whatsoever, although it is in the exhaust path after the turbo.

 

The test pipe will still make more power than an O2 housing/HF cat combo. As far as I can tell all HF cats will cause the occasional P0420 CEL (some more than others) ... there is a mechanical fix for that, though. IMO, if you're going to go with a new DP and HF cat, at least go with a 3" setup. No point in spending money on something that may compromise future mods.

l8r)

 

well i meant to ask that in a question rather than a statement, but anyway you just answered my question.. wartalon


Ok.. so I guess I'll need to get an 02 housing and hfc or testpipe


but about high flow cats.. I dont want to get a check engine light and I want to pass emissions because my evo is a daily driver


Actually I think the Helix High flow cat will work out for me.

 

any high flow cat can potentially cause a CEL - none can guarantee that they won't. If you install the anti foulers, you will not trigger the CEL. Sounds odd, but several test pipes will NOT cause a CEL due to the design of the 02 sensor portion - all of the ones on the market are knock offs of Ultimate Racing's, which is far and away the most popular test pipe for the Evo. They also offer a high flow cat if that is more your style, but again, they sometimes cause the P0420 code

As for an 02 housing...have you done a turbo back exhaust yet?

 

Not a turbo back exhaust.. I'm getting a downpipe probably helix preferred HKS but the price is outrageous, i'm looking at the helix HFC too

I have the HKS high power 30th anni catback

Which test pipe do you reccommend then?.. I figured all test pipes would cause the CEL due to lack of catylic efficiency or whatever.

I saw that the perrin comes with an 02 simulator which should fix that but what about emissions? Some sites said the helix HFC pass emissions in Cali so I'm figuring it will in MA.

 

I doubt the Helix HFC will pass emissions. I can smell exhaust fumes at idle sometimes even after my car's warmed up. I've failed enough emissions tests w/ HFCs on my DSMs to know that stockers are best. Always keep it to swap back for testing!

 

Port your stock o2 Housing, put a nice UR cat delete and problem solved