msuc5vette

Those of you who removed your cats, how bad does your exhaust smell?

sick_vette

It smeels a bit, but nothing to crazy. At first it really stinks, not sure if it gets less or you just get used to it.
Not to big of a deal in my opinion. :cheers:

Z06TheKid

:iagree:

Y2Kvert4me

On my car, it's noticible, but not bad. To me it smells like an old 60's car.

I know a lot of people say the smell is overpowering and actually makes their eyes water...I don't know if the difference is in the tuning or what, but I don't find mine offensive at all.

:cheers:

alexWS6

Its the smell of horsepower, how can you not like it? ;) Only complaint I have is that it if you are behind that exhaust it sticks to your clothing. you go in somewhere and sometimes people notice it. Rarely is it that bad though, how often do you stand behind the car while its running?

msuc5vette

Mine is pretty nasty when you stand right by the back of the car for a long time.

It doesn't make my eyes water, but it wouldn't impress the ladies either.

I assume it would smell worse the richer the fuel right?

I was told by the shop that tuned my car that if I put an 1/8th inch hole in my throttle plate it would idle a little smoother, and start easier when warm. It hasn't been much of an issue so I haven't done it yet, but I am wondering if it would lean out my idle a little and cut down on the smell.

RWhite

I just gutted my cats a few weeks ago and was surprised how little the smell got worse. It was not as bad as my '97 Mustang Cobra for sure. BTW, my gas mileage has increased over 1 mpg w/o the cats. I did not retune the car since I am putting on Random Tech cats and xpipe in the next week or so. It is slightly louder at idle but not more than 1 dB :D louder!

Stellar112

Maybe I'm lucky? No smell whatsoeva and the rumble is more than worth it. :yesnod:

Bink

I am totally confused :confused: . Why does the engine stink with the cats off. They didn't stink in the days before cats (preOBD1 and OBD11). They did stink with the early style cats->sulfur. :confused: ???????

irfgt

You probably just don't remember how bad they smelled. Converters are the greatest automotive invention since the wheel.

larrysb

The stink is unburned HC (fuel and remnants of partially burned fuel).

The smell is best described as "that lawnmower exhaust smell".

Exhaust in the old days did smell of HC. Get behind a well tuned 60's muscle car and you can relive the old days. All that unburned stuff in the air was linked to smog, lung disease, elevated lead levels (from leaded fuels) in the blood of children and all kinds of other wonderful stuff like that.

Your C5 may also smell, since it will have nothing to consume any leftover hydrocarbons in the exhaust if you remove/disable the catalyst. The engine's tuning will be expecting the catalyst in place and may not be able to adequately compensate for the lack of catalyst.

It's like tossing your trash and cigarette butts out the window. Same deal.

If you find you just have some compulsive need to disable the cats, then purchase an off-road X pipe and O2 sims. Get your PCM tuned for the no-cat operation for your 5hp gain, otherwise you'll probably lose some power on a stock motor.

When you come back to your senses, you can then re-install the cats.

Or get the electric cutouts, so you can switch to open exhaust, impress the ladies, win the race or whatever you think you need to do, then switch it back to the catalyst to prevent stinky smells and that pollution thing.

The rotten egg smell is from contaminated fuel (sulfur) being oxidised by the catalytic system. That's a different smell though.

Racer1x

Take a drive behind someone in one of your corvette cruises that doesn't have cats, you'll see what we are talking about. :U

Bink

The smell is best described as "that lawnmower exhaust smell".

Exhaust in the old days did smell of HC. Get behind a well tuned 60's muscle car and you can relive the old days.


I was raised around automotive and aircraft shops, racing and motorcycles. I honestly never thought of 2 or 4 stroke exhaust as "stinky", I thought you Guys were referring to the "sulfur "smell.
I guess it depends on your perspective. I like the smell- it's like Grandma's kitchen.........pleasant memories! :lol: :D :thumbs:

MTWallet

When I first started my car after my H/C was complete I had the ORP's installed. It sounded raspy and really stunk like unburned fuel. After I had it all tuned up it wasn't as bad but it still stunk. I put the cats back on and the sound changed to a lower, more powerful rumble my nose and eyes thanked me.

Big Casino

:lolg:

larryb, I think you have a converter stuck up your hole


[Modified by Big Casino, 9:43 PM 8/4/2003]

aaaaa

"I am totally confused . Why does the engine stink with the cats off. They didn't stink in the days before cats (preOBD1 and OBD11). They did stink with the early style cats->sulfur. ???????"

That's how I remember it. When they first started using cats the smell was awful! A well tuned engine has very little smell.

And as for throwing garbage out the window-this is a forum for high perf. cars-please keep your political opinions out of it. :rolleyes:

aaaaa

BTW, RWhite- how did you gut your cats? I want to do mine.

C5-VERT

Mine did not smell that bad with stock cubes + cam but when I put my big cube motor in the smell is pretty bad. But for 20+rwhp and torque is was worth it.

AFVETTE

I still don't get the "removing cat" routine. If all your after is more sound buy a better exhaust system, if your after another 5 or 10 HP there are other cleaner ways like headers to do that. That's what I'm doing. FLP's with high flow cats.

Removing your cats IMOP is a :nono: :nono: and not worth the damage to the atmosphere.

Tom
USAF Retired

BTW: I'm selling the FLP ORP's that come with the kit if anyone is interested. For track use only :jester :jester


[Modified by AFVETTE, 5:28 AM 8/5/2003]

Bink

:thumbs: :D