No cat and changed mind back to a cat?

[chrisbruck]

Curious how many of you pulled the cat for a bypass pipe or premuffler and decided later to put the cat back on? Looking for different reasons why you decided to put the cat back on.

I pulled mine and installed a bypass pipe with the stock muffler with a modified 2nd outlet on the passenger side. Sounds pretty nice but on the louder side.

My dilemma is the much more noticable smoke due to worn valve guides (and new SW chip!). I'm about to put the cat back on till I save up for a top end rebuild.

[wes_r]

Going to put the cat back on this weekend. The noxious smell has been bugging me for a while.

Also put on a new M&K muffler last weekend. While it sounds great, I'd like to take the edge off of it so-to-speak.

[James Brown]

the oil will foul and might cause the converter to fail. if you can get by till the top end, that might save the cost of a converter. BTW, i tried a experiment with my 81, stock exhaust, euro muffler and regular cat, sport single in/out muffler. I did not see any increase in performance. A little louder with the euro muffler but thats it. the bad part of the system is the crossover and 6 into 1 headers that really choke the system. backdate would be the way to go. with a chip (3.2 i am guessing) and a good flowing exhaust will waken up that engine. the smoke only bothers the people behind you!!

[wholio94112]

i got hold of a fabspeed SS beauty so i switched it from stock muff/cat on my 86 930...the power was phenomenal, almost too cumbersome and uncomfortable to hit boost...and the low guttural growl was NOT the sound i want in a porsche...1967 camaro, maybe, but not a european sportscar...then there's the smoke and noxious, invisible fumes...i felt guilty when i wash't even wanting to be vain...so I'm back to stock, i pass CA smog, and am a bit lower under the radar...

[chrisbruck]

yeah, I think the cat's going back on this weekend... I like the Wong chip but the added smoke and smell isn't fun in daily driving traffic.

[SiberianDVM]

I really didn't notice any increase in smoke or fumes when I switched my old cat for a M&K premuffler. I put in a SW chip and a new O2 sensor at the same time. Heck, the looks alone of the M&K premuffler over the old rusty cat is enough reason for me to keep it.

[djcdmv]

Over the summer I got a SW chip and a cat bypass. Like many, I couldn't stand the noxious fumes and additional smoke so the cat went back on. Kept the SW chip in.

[911 Rod]

I've had mine off and on a few times and did not notice any difference

[Arne2]

No smoke from mine, but there are some fumes. I've considered re-installing the cat, but it's never been bad enough to become at all important.

[DG624]

I took it off for a bypass from M&K but kept the CAT and had it ceramic coated to eliminate rust. I use the bypass for SOLO and put the CAT back during the winter or when I am not driving hard. I didn't notice any fumes but I wanted to have an emissions test to see the difference.

[nineball]

removed they 83SC and replaced it with a dansk pre-muffler. seemed to lower (deeper) the sound under 2k, after 2k sounds the same as stock. i did notice a little more on the fumes side but no smoke.