Stinky car after cat-bypass...

[carnutzzz]

My car is pretty stinky now without the cat on (removed for off-road use only).

I see people switching to the cat-bypass all the time, but no mention of the stink.

I rather like the smell (smells like a racecar), but I'm wondering if mine stinks more than most?

[tcar]

Still have your lambda hooked up?

Guessing it's running waaaay too rich.

[joe payne]

YES, Your car freaking reeks! I can can smell it all the way out here in California.

[carnutzzz]

Originally Posted by tcar

Still have your lambda hooked up?

Guessing it's running waaaay too rich.

What's the best way to "tune" the car after cat removal? I intend to get a Wong chip also.

[tcar]

You should have someone with an exhaust probe set the mixture - usually P-car mechanic.

Setting it too lean, by guesstimate, can damage the motor.

Fix this before you chip it.

[joe payne]

on a more serious note. If your cat bypass is new, you may be smelling the paint curing on it. The smell will go away with time.

[carnutzzz]

Originally Posted by joe payne

on a more serious note. If your cat bypass is new, you may be smelling the paint curing on it. The smell will go away with time.

No, this is exhaust gas. It does smell like it's running rich.

[my911cab]

I have a cat by pass and it definitely smells from like exhaust. I did the custom SW chip to match and it runs awsome. I picked up more HP and torque which is what I was looking for. I can live with the smell for the most part...but definitely a difference.

[Steve W]

Removing the cat, you'll smell the exhaust more, but it should be no more than any other sports car that you removed the cat off of. In other words from the driver's seat, it shouldn't really be noticeable, and if so, perhaps occasionally such as when backing out of a parking space. If it's excessive, you may have some issues that need to be sorted out.

[my911cab]

What Steve described matches my experience with my car. I smell a little more because I have a Cab and drive with the rear window zipped down. When I have the rear wiondow sipped up it only get a whiffs of it when the wind us blowing from behind. I got used to the exhaust smell and don't really notice it as much. Well worth the upgrade... Chip and Catbypass... I really think that custom chip is the way to go.

[Buckterrier]

Mine smells also but not at all in the car. That's what cars pre cat smelled like.

[old man neri]

O2 sensor maybe? When was the last time you tested it or had it replaced?

[tcar]

Back to my first question: is the lambda (O2) sensor hooked up?

If not, try hooking it up (assuming your bypass has an 02 port) and see if it helps.

If it is, try unplugging it (inside the engine compartment by the left valve cover); aee if that helps.

Let us know.

[450knotOffice]

Mine smells a tiny bit, but I kind of like it in an old school sort of way. And yes, an O2 sensor installed in the Cat bypass will lean it out a bit. Check that.

[aigel]

You are smelling the smog causing elements. All the older cars smell like that. I can smell them in traffic actually.

George

[carnutzzz]

O2 sensor is hooked-up. I don't think it's orginal to the car- it looks pretty new still. If it is original it would have 83k miles. Car runs excellent otherwise.

It could have been a little stinky since I was doing a few full throttle test runs, then was stopped with the windows down.

After I backed into the garage my lady friend didn't want to stand in the garage at all. I remember running cat-less in High School in my V8 Firebird and my dad complaining that I was stinking up the house after backing into the garage so this sounds pretty consistent I guess.

[tcar]

Try unplugging the O2 sensor and see how it smells.

Won't hurt anything. My wrench unplugged mine, said it runs smoother, doesn't 'hunt' as much.

[911st]

I am not an expert but would suggest first making sure your maintenance is up to date with a fresh air filter. Including testing to see if the O2 is getting lazy and that your mix at idle is at spec.

Then, get the SW chip. I believe in testing the A/F ratios on the dyno and like the custom chip option he has. To do this, have the tec remove and upplug your O2 and put their wide band O2 in its place.