[MKILLER]

Help!!! Not sure on what is the difference? Can you help or point in the right direction.
Thanks!

[Mike@N54Tuning.com]

Originally Posted by MKILLER

Help!!! Not sure on what is the difference? Can you help or point in the right direction.
Thanks!

catless ar design downpipes Best you can get IMO

In terms of performance this is what you are looking at from best to worst

1) catless downpipes (most free flowing)
2) performance catted downpipes (better then stock but more restrictive then catless
3) stock catter downpipes (most restrictive)

Hope that helps

Mike

[Daya]

On a basic level compared to catless the catted is a little bit more restrictive and produces less power increase but it is better for the environment, will not produce the smell of gas, will probably not trigger an O2 sensor code and will probably pass your emissons test.

The catless is non-restrictive and produces a little bit more power, will produce the smell of gas, will trigger an o2 sensor code unless you install an O2 simulator and you will probably fail your emissions test.

With that being said I chose catted for a modest power and none of the issues associated with going catless. Catless will also be a little bit louder than catted. Catted is also more expensive.

[luca335i]

If your keeping the secondary cats go catless. If you have or planning on going with the catback I'd go catted. I went with catted dps and a catback. 40 pound weight savings for the catback, no smell and added power. It's a win win and I love the setup.

[McMuffin]

Originally Posted by Daya

On a basic level compared to catless the catted is a little bit more restrictive and produces less power increase but it is better for the environment, will not produce the smell of gas, will probably not trigger an O2 sensor code and will probably pass your emissons test.

The catless is non-restrictive and produces a little bit more power, will produce the smell of gas, will trigger an o2 sensor code unless you install an O2 simulator and you will probably fail your emissions test.

With that being said I chose catted for a modest power and none of the issues associated with going catless. Catless will also be a little bit louder than catted. Catted is also more expensive.

This is true. Gas smell isnt that bad tho, well atleast comparing it to my Civic

[enrita]

get catless, waste of money to get catted. The point is to remove the worse restriction of the system and keep temp low.

[SV Concepts II]

I would go catless for better flow. But if you have a sensitivity to the smell of fuel (you will slightly smell it while the car is stopped) then you might want to stick with a catted downpipe.

[MKILLER]

Cool! Thanks guys for all the help! Cant wait to get purchasing. best place ...best price?????

Originally Posted by Ali@Jlevi SW

I would go catless for better flow. But if you have a sensitivity to the smell of fuel (you will slightly smell it while the car is stopped) then you might want to stick with a catted downpipe.

[TigerDejan]

AR Design Group Buy ... 599+shipping+o2 sims

[bmw3355]

if you have catted downpipes on stock exhaust can you hear a differnce? or does it sound the same?

[DefBringer]

Operating a vehicle in the US without a catalytic converter is illegal.

That said, I have done it in a few of my cars and never once had any trouble with my state inspection.

But someone should point that out to the original poster.

[DefBringer]

BTW, does anyone have a dyno of a car before/after downpipe installation? Preferably on stock tune?

[enrita]

dont have a dyno sheet but my car picked up 25 whp with AR catless dps and Helix intercooler on stock boost.

[klipseracer]

Originally Posted by DefBringer

Operating a vehicle in the US without a catalytic converter is illegal.

That said, I have done it in a few of my cars and never once had any trouble with my state inspection.

But someone should point that out to the original poster.

Thats not true in all of the United states. In Oregon everyone drives straight pipes and there is no emissions test to pass. At least when I used to live there. Registration is extremely cheap and no CARB laws.

[DefBringer]

Originally Posted by klipseracer

Thats not true in all of the United states. In Oregon everyone drives straight pipes and there is no emissions test to pass. At least when I used to live there. Registration is extremely cheap and no CARB laws.

It's a federal law.

http://www.catalyticconverter.org/law/

Kansas does not smog check either, lots of people go catless without a problem. But that doesn't it isn't illegal.