Overpipe and Frontpipe (CA Questions)

[FUN BRZ]

Hey Guys,

I'm planning on upgrading my exhaust system within the next month. Well 90% positive I will depending on how the answers to my questions turn out.

My main concerns are - will an overpipe and frontpipe effect our cars when we need to get it smogged in the future? Basically will it pass smog? Or will I have to keep the stock parts and throw them back on when I get my car smogged.

Another question is whats the difference between a frontpipe with and without a cat? Should I purchase one with or without one?

Lastly, what happend to the Perrin frontpipes they manufactured? Can't see to find it not even on their site...

Sorry if I sound like a noob, just never upgraded any exhaust systems on my cars before. I've mainly worked on bikes (I've put my Gixxer back together more times that I've wanted ) and as for cars only done suspension and wheel upgrades.

Thanks BTW Guys!

[ganjara]

catted Nameless front \ overpipe with the resonator is the best I think. Cant go wrong

[mkivsoopra]

Technically, you will fail the visual inspection.... But that's assuming they'll actually see it. You might pass the sniffer if you get a catted front pipe. It'll be best to keep the stock stuff around for these occasions.

Originally Posted by ganjara

catted Nameless front \ overpipe with the resonator is the best I think. Cant go wrong

I used to have that setup, and I agree.

[Carlitoz3]

Originally Posted by FUN BRZ

Hey Guys,

I'm planning on upgrading my exhaust system within the next month. Well 90% positive I will depending on how the answers to my questions turn out.

My main concerns are - will an overpipe and frontpipe effect our cars when we need to get it smogged in the future? Basically will it pass smog? Or will I have to keep the stock parts and throw them back on when I get my car smogged.

Another question is whats the difference between a frontpipe with and without a cat? Should I purchase one with or without one?

Lastly, what happend to the Perrin frontpipes they manufactured? Can't see to find it not even on their site...

Sorry if I sound like a noob, just never upgraded any exhaust systems on my cars before. I've mainly worked on bikes (I've put my Gixxer back together more times that I've wanted ) and as for cars only done suspension and wheel upgrades.

Thanks BTW Guys!

You will need the cat to pass the smog check.
But from what I read in the forums you can delete one and still be good.
The 2nd cat is in the OEM headers.

[bkblitzed]

The only cat that's monitored is in the headers. If you're worried about smog, just put 2 gallons of e85 in a tank of gas and you'll run clean, it will mess up your afr's though.

[leicaboss]

Originally Posted by mkivsoopra

Technically, you will fail the visual inspection.... But that's assuming they'll actually see it. You might pass the sniffer if you get a catted front pipe. It'll be best to keep the stock stuff around for these occasions.



I used to have that setup, and I agree.

What made you leave it! I've got the Berk FP with a HFC and I'm tempted to pawn it to buy the Nameless Catted FP/OP + Res' if it actually helps with noise.

[finch1750]

The front pipe has a cat so replacing it even with a high flow cat will technically fail. Overpipe is fair game.

Catless will generally have a little more rasp to it.

Perrin stopped making any parts that mess with cats, hence the front pipe disappeared.

So keep your stock stuff to swap back in 5 years and get whatever pipes you want. It takes 20 minutes to swap and you know you will pass instead of hopibg you will pass.

[PMok]

Here's a simple diagram of the whole exhaust system (courtesy of Perrin):


There's a cat in the header, and a cat in the front pipe. I don't think anyone knows for sure, but removing a cat from one part and leaving the other *might* still pass the emissions test. One solution some might be pursuing is to remove one (e.g. buy a catless header) and upgrade the other (e.g. buy a catted front pipe) that will hopefully perform better as a sole cat than the other two might perform on its own. We'll have to see what happens to the CA smog procedure in the next year or two though, tailpipe emissions may no longer be tested soon.

Originally Posted by bkblitzed

The only cat that's monitored is in the headers. If you're worried about smog, just put 2 gallons of e85 in a tank of gas and you'll run clean, it will mess up your afr's though.

that seems kind of hit or miss... if your AFRs are messed up enough you will end up throwing a CEL and then you won't pass.

[mkivsoopra]

Originally Posted by leicaboss

What made you leave it!

You'll see tomorrow

[leicaboss]

Originally Posted by mkivsoopra

You'll see tomorrow

Once I put all my stuff on, we'll be more matching - two white BRZ's with aftermarket tails and a reverse cam - unless my memory failed from concussion lol (not really that funny though).

[finch1750]

Originally Posted by PMok

Here's a simple diagram of the whole exhaust system (courtesy of Perrin):


There's a cat in the header, and a cat in the front pipe. I don't think anyone knows for sure, but removing a cat from one part and leaving the other *might* still pass the emissions test. One solution some might be pursuing is to remove one (e.g. buy a catless header) and upgrade the other (e.g. buy a catted front pipe) that will hopefully perform better as a sole cat than the other two might perform on its own. We'll have to see what happens to the CA smog procedure in the next year or two though, tailpipe emissions may no longer be tested soon.





that seems kind of hit or miss... if your AFRs are messed up enough you will end up throwing a CEL and then you won't pass.

Yeah, I still cant figure out if/when that change is coming. Its like its optiobal at this point but not mandatory. Not having a sniffer would make all of this way easier. A buisness selling "heatshields" for aftermarket pipes would make a killing. Lol

[tbertran]

Originally Posted by PMok

There's a cat in the header, and a cat in the front pipe. I don't think anyone knows for sure, but removing a cat from one part and leaving the other *might* still pass the emissions test.

Keep in mind that to avoid a CEL, the only cat you can safely remove is the one in the FP. Without a tune, that is.

[leicaboss]

People have been doing the fake cat pipe (test pipe with shields):

http://forums.evolutionm.net/evo-how...-like-cat.html

Perhaps we can all visit the salvage yard one day with tools and make some lol.

[FUN BRZ]

Thanks for all the info peeps!


After reading everything, seems like I'm just going to stick with getting a cat system and an overpipe for now, the front pipe can be something I do in the future.