Secondary cat bypass - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Escott1622 · 02-12-2021, 07:45 AM

So I’m picking up my new 2001 986 soon and I want to get some parts for it now. I plan on sending the exhaust out to fister to get it modified and I was wondering if anyone had experience with the circuitwerks secondary cat bypass pipes. I was looking on their website they aren’t labeled as bypass pipes they call them test pipes for 158$, is this the same thing just different name? I plan on seeing how the exhaust sounds without the pipes then with the pipes I’m not trying to go too loud since what I’ve seen so far the fister is decently loud

Jgkram · 02-12-2021, 08:31 AM

Yes, for your purposes test pipes and bypass pipes are considered one and the same. I bought a used set of Top Speed pipes from James (forum member) basically to continue to lose a little weight in the back. As far as sound there was a slightly noticeable deeper tone during hard accelerations but nothing that would compare to what you are about to do with the Fister mod.

Escott1622 · 02-12-2021, 09:37 AM

I’ll probably put the fister on but if it’s to loud I’ll put the original cats back on. It sounds good but a lot of videos I see it seems to be very loud and somewhat raspy but in others it’s not so that’s why I didn’t want to spend crazy money on pipes

willw · 02-12-2021, 10:19 AM

They call them test pipes because it is illegal in most states to eliminate cats.

Escott1622 · 02-12-2021, 11:04 AM

Is there any process for installing these? Can I just order them and bolt them right on with the supplied hardware no welding or anything

Jgkram · 02-12-2021, 11:23 AM

Willw is right. In some states you will not pass inspection with a delete. However in my state, because the car is 20 years old, emissions is no longer a requirement. Besides most Boxsters have two sets of cats (not sure about the early cars) and elimination of the back set does not cause problems. James (NewArt) posted a great video on youtube when he installed his (now mine). The only thing I would recommend is that you wrap the pipes in some type of heat wrap because the mid pipes had a heat shield located strategically to protect the rubber boots on the axles. The bypass pipes run really close to those boots and if you don't shield them from the heat you could accelerate their deterioration. I also soaked the bolts in PB Blaster before disassembly and had no trouble at all removing them. Make sure to use new gaskets when you reassemble. Good luck.