Imamotohead

I’m considering purchasing a set of long tube headers along with an x pipe. I have always figured I would get a catted x-pipe but now I’m reconsidering. I live in Kansas so I don’t have to worry about emissions testing. I have always heard about the smell associated with off road x-pipes. Can those out there with off road pipes share your experience? Is the fuel smell enough to worry about? Also I assume catless pipes will be louder. I’m all for a performance improvement but don’t want to compromise driving comfort. The cost advantage of the off road pipes is sure appealing though. As always your experience, thoughts and opinions are appreciated! Thanks!

Brad Kirby

I have Kook longtubes with 200 cell cats on each side, X pipe, and Borla Stingers. I am SOOOO glad I have the cats. You can't sneak up on anyone in this car. Cabin noise while accelerating drowns out the stereo. Crusing noise is low enough to have a conversation, though at increased volume. Unless you want to wear hearing protection, get the cats.

ASRoff

oh brother... ok... the exhaust system you choose will determine sound and volume... if you want loud get the stingers or attacks. if you want some sound but no drone get the magnaflow street series.. while the cats will help dampen the sound, a set of resonators will do the same job. tock cats will probable use 10-15hp more if they are old... performance cats typically cut the power loss in half (5-7hp) this is assuming the engine is stock.. if you don't need them then drop a little weight and gain a little power and get rid of the cats... if you don't want drone get something that either has resonators or is closer to a stock exhaust system.

Rx7Rob

The smell is the same as 60's and early 70's muscle cars.

Smell and sound are subjective so only you can decide.

I don't find the smell objectionable but I've always been around old cars, race cars, and two strokes. The smell is waaaaaaay less than an uncorked rotary (a rotary is like getting maced if it hits your eyes).

I think the sound is better without but it can still sound good with the cats.

foggy

I faced the same decision last year.. I ended .up with the catted Kooks System..
I really like it. I did not change the mufflers at the time... So only change was the Kooks with the X pipes and cats.. The aftermarket cats really don't cost any horsepower..
I decided I would go cats .. I'm in KS too, and even though no inspections NOW, there
might be in the future. I did the the "NO AIR PUMP" Headers.. WOW.. What a nice clean up of the engine bay.. Just had to tune out the air pump.

grantv

I opted for cats to help the environment. I sometimes wonder though what's worse; no cats or eventually maybe getting rid of used cats.
I wish my car was a bit louder, so have actually considered removing them.

OleStraightStick

No kitties here.. I wanna make sure everybody in my neighborhood is awake when I drive through

SPEED750

The problem is the smell without cats. I run LT headers, Xpipe no cats and ZO6 mufflers. Sounds great and the smell doesn"t bother me UNTIL the WIFE gets in the car.

"Why does it smell like gas honey ?" "Is everything OK ?" "Is this normal ?" Then if you get stuck in a drive thru or long light with the top off, it can get strong. I'm also running a BTR stage 1 cam.

bwill03z

If you are trying not to compromise driving comfort and you aren't trying to squeeze as much hp out as possible then I would go with cats. I've had both, and I prefer cats. Going catless is fine while driving down the highway but when you stop at a light or pull into a garage the exhaust smell gets pretty stout real fast. The lower cost and few extra ponies w/out cats is nice but you mentioned driving comfort so I would get a set of high flow cats and call it good. I have 200 cell count metallic core cats and I'm happy with them.

OleStraightStick

It all boils down to one thing, period- sound.. the power increase significance is slight.. I cut mine off after 8 years of running Borla straights and long tube headers with an x-pipe only because I got bored and wanted it louder.. & believe me, it doubled in dB just from deleting the 2 main cats (pup cats were already deleted when installing LT’s)..

I run zero exhaust back pressure/restrictions, and hardly smell anything at all.. to me that is a complete non-issue..

Ask yourself, do you want loud or not?

Yes- no cats
No- leave cats on

redzg

Sorry, but it's more than the sound. I lived in the Los Angeles basin in the late 60s and into 70s -- when it became impossible to see the Hollywood sign or the San Gorgonio mountain range, due to smog. Today, two decades after implementation of serious anti-pollution regulation the smog is significantly reduced -- and not just in Los Angeles...
And, yes, my other car is a Subaru.

grantv

Thus the reason I opted for cats; no regulatory requirements, just wanted to.
I don't understand your last sentence...

redzg

For some, concern for pollution or the environment is 'liberal' thinking, and many liberals are noted to be Subaru people.

Kansasz06

OleStraightStick

Fair enough, but I’ve put only 30K mikes on the vette in the 12 years I’ve owned it, and my car not having cats isn’t gonna put us into the next ice age.. our south Alabama air is good’n fresh, and my car ain’t gonna change that, so for me it was/is 100% about the sound.. & my conservative Eagle Scout self is guilt-free about it, too

grantv

Wow, never heard anything like that before. I am somewhat concerned about the environment, but honestly don't know what being a liberal is, and never owned a Subaru. Maybe I should delete my cats.

vettenuts

I'm not liberal but have been looking at Subaru's. Guess I am more screwed up than I thought I was

I would install the cats because of the smell alone. You can get some good flowing cats that only cost about 5hp.

gimp

We all need to breathe the air. Maybe don't be a dick and don't drive around without cats. Your car is a street car, not a race car, the extra 5 horsepower isn't a big deal.

whowon

From a guy without cats, get cats.... Mistake I would like to correct someday.

Gordy M

Unless you have a highly modified car you will only lose 2-2.5hp at most with the cats. We had a club member years ago run his stock Z at the drags and wanted a little more speed. Removed the cats and his ET and trap speed remained the same, no difference. Since then he has spent $$$ on increasing his HP but went with catted LT headers.