I previously had a 997.2 turbo with a catless GMG exhaust and I found the smell to be overwhelming at times. I eventually swapped the catless sections for a set of 200 CEL cats but the interior still retained the gassy smells for the remainder of my ownership of that car (1 year).

Is the 991.2 any different? I love the leather smell of the interior and I don’t want the same situation as I had with my 997.2 where the gassy smells lingered in the interior.

Catless owners, weigh in…

Do 100 CEL cats still smell?

 

It's no different. You can definitely still smell it.

 

I only notice it standing outside the car, but I don't have the windows down unless I am driving at some speed.

 

Non-issue for me and I drive my catless .1 with the windows down all the time.

 

LOL, there was a reason that catalytic converters became required on all gasoline-powered vehicles starting in 1975. I remember the days when the skies over major cities were brown many days a year. I also remember the days when all cars smelled like gasoline inside and out.

It's kind of like cigarette smoke in that 50 years ago we were so used to it everywhere, and we thought that's the way things were supposed to smell.

 

It's pretty bad upon startup when cold. Once warm it's better. Obviously a tune can make it worse or better.

 

I have a 991.1 TT Cab with Kline 100 cells. I notice a slight smell on cold start. Otherwise, nothing.

For comparison, I came from a BMW M3 with a catless exhaust. This is nothing like that except for maybe the first 30-60 seconds.

 

I only notice smell on the start up.
After warm up and the R's drop, none.

 

Went from 200 cell on a 4S to 100 cell on Turbo S, Both cars you can smell something on cold start but its short duration

 

I have 100 cel cats on my 991.1 Turbo S cabriolet with a dyno-tune by AIM performance.
It has 3" exhaust also and there is no smell at all.

 

It definitely stinks and you can smell it during idling when you have the windows down. But it's a great trade off to get better exhaust notes!!!

 

how did going from 200 - 100 effect the sound?

 

2 totally different set ups, the 4S was 3.0 and had PSE stock, once I put in the Soul 200s it sounded great and turbo spooling was quite evident. The TS 3.8 muted exhaust got better with the Europipe but thats not known to be a loud set up and sounds way different than the 3.0/PSE

 

Here are some vids of mine, Speedtech 3" with 100 cel cats



Here is one with same exhaust set-up from in car before I tuned it

 

Theres nothing like the smell of unburnt hydro carbons in the morning...

Cattted or not, I can still smell the difference on start up, then don't really notice it after.