CAT bypass for 3.2
 

Who makes a CAT bypass pipe for the 3.2 Carrera motor? I have an 88 which is exempt from emissions testing. I plan to keep the O2 sensor in place but wanted to remove the CAT and just run a pipe into the exhaust system.

I have the Fabspeed Euro Pre-Muf on my 88. Lots of choices though once you decide how much you want to spend.

Once in a while you can find a used factory pre-muffler. I bought one that came with the O2 sensor bung a while back for my 3.2.

I used an M&K premuffler to replace the cat on my '88 Carrera and I am very pleased with the result. It fit perfectly. Here is a link to the thread about installing it.

http://forums.pelicanparts.com/porsche-911-technical-forum/515525-criminal-behavior.html

The only downside was that the amount of oil the engine was burning became immediately obvious with the cat gone.

MK is one source, got mine from our host. I have the cat by-pass and its definately louder than the cat (destroyed/melted inside) that I removed. It was $100 cheaper than the pre-muffler by MK but in retrospect, think I would have gone that way. Fit and quality seems very good. I called and spoke to Ben at MK and he told me that the sound from each is similar, I've heard others says the pre-muffler is less noise.
Not sure the cat bypass is shown on Pelican any longer, maybe he's only offering the pre-muffler.

Stock... a Porsche Euro premuffler will not have an O2 sensor bung, as the cars were not feedback control-looped without a cat. If you find one like this, the O2 bung was a later addition. I mention it only in case someone buys a stock unit and notices the bung isn't there.

+1 on M&K premuffler

Bought a Bursch premuffler from our host in the late 90's. Still in great shape but one of these days I'd like to get it powder coated. It does get surface rust even though I painted it wife muffler paint. No problems with fit. I used to take it off to pass Houston emissions standards for NOx but moved to the Texas Hill Country which does not test.

Another vote for M&K premuffler. Have one on the 88 carrera. Perfect fitting quality product.
Nice sound with stock muffler. Has O2 bung.
Gary

How much smoke does the CAT hide?

With a pre-muffler are you trailing smoke wherever you go?

Not if your engine is in good mechanical condition.

+1 m&k

I have an new M&K available thanks to a customer that dissappeared after we brought it in. If you are interested, drop me an email and we can make a deal.

info@pacificwesternperformance.com

cheers