Akra slip on what xpipe = pass smog and no CEL??

[ES_TRADER]

Ok so via the other thread I kno the challenge street is capable of this BUT are there any other options that are bolt on and don't require cutting oem pipes? I want to keep oem ones just in case I need to swap it out in the future. What options do I have without going custom or cutting?

[kitw]

The challenge street will pass the tail pipe and OBD-2 tests, but won't pass visual since it eliminates the secondary cats. (most places won't catch this)

None of them will produce power without removing the primary cats, though. You might as well do a Challenge Sport, Turner test pipes or Innotech if you don't mind some rasp. The Gintani/MXP/Fabspeed that put HFCs in the same position as the stock cats won't make power like the the ones that move the cats downstream.

[Green-Eggs]

Try the Active X-pipe

[GTM_Challenge]

Originally Posted by kitw

The challenge street will pass the tail pipe and OBD-2 tests, but won't pass visual since it eliminates the secondary cats. (most places won't catch this)

None of them will produce power without removing the primary cats, though. You might as well do a Challenge Sport, Turner test pipes or Innotech if you don't mind some rasp. The Gintani/MXP/Fabspeed that put HFCs in the same position as the stock cats won't make power like the the ones that move the cats downstream.

Our street X pipe showed gains across the entire power band actually, even with keeping the stock primary cats. It has been verified by some of our customers dynos as well.

[Omerta]

Originally Posted by richpuer

Ok so via the other thread I kno the challenge street is capable of this BUT are there any other options that are bolt on and don't require cutting oem pipes? I want to keep oem ones just in case I need to swap it out in the future. What options do I have without going custom or cutting?

if you are worried about the smog, just get a louder exhaust than the Akra and keep the stock X-pipe. The Akra needs a catless X-pipe to shine its best in my opinion. Get a Challenge catless race X-pipe and a tune then when smog check time comes have your oem X-pipe reinstalled. Yes it is going to cost more in the end but you get the better setup that way.

[rockd]

Originally Posted by richpuer

Ok so via the other thread I kno the challenge street is capable of this BUT are there any other options that are bolt on and don't require cutting oem pipes? I want to keep oem ones just in case I need to swap it out in the future. What options do I have without going custom or cutting?

Every x-pipe that is bolt-on will either eliminate or replace the primary cats (due to the primary cats and secondary cats being one piece). Eliminating them will definitely trigger a CEL, and replacing them with HFC's will *most likely* cause a CEL eventually.

The only way to ensure no CEL and to pass OBD2 readiness tests is to NOT touch the primary cats, which means cutting the factory exhaust system.

PM me if you have any more qs.

[J08M3]

or just stay OEM

[Malek@MRF]

Catless system's will not pass emissions. Even sport catalyst systems will not pass the actual sniffer test. Some states don't have sniffer tests, but the ones that do, catless systems will not pass under any circumstance.

If emissions is of concern, the best thing to do is get a louder exhaust system and keep the midsection stock.

[phusion974]

You can go with the Challange, Gintani, Active, or Akrapovic X pipes. There are alot of options out there.
Personally I would go with either the Challenge Race or Gintani Catless.

[Sean05]

as long as you dont take your OEM primary cat... you can pretty get what you want.

once the primary cat is remove CEL will always come up no matter what. (although some aftermarket xpipe claims that there xpipe will not throw a cel...)

[Singletrack]

My fabspeed hfc's have not thrown a cel since I installed the extenders they now include with all systems. Before that, it tripped every other day when cruising.

[ES_TRADER]

Originally Posted by GTM_Challenge

Our street X pipe showed gains across the entire power band actually, even with keeping the stock primary cats. It has been verified by some of our customers dynos as well.

so from what i understand, going with this option, id have no choice but to cut the oem pipe section behind the primary cats, and it wont trigger any issues?

[MJM]

I have the Akra Slip-on and the Challenge "Street" X-pipe on my 2011 E90 M3. No issues with ECU errors and no need for the Akra CEL Delete-R.

[kitw]

Originally Posted by GTM_Challenge

Our street X pipe showed gains across the entire power band actually, even with keeping the stock primary cats. It has been verified by some of our customers dynos as well.

Not on my car. It was well within dyno error. (both the Fabspeed and the Challenge Street X pipe did not make any meaningful power)