melman911

Ok so my new Fabspeed 200 cat comes in the week. Just eyeballing the job it looks pretty straight forward. Want to replaced the oxygen sensor while I'm at it. Anything that might surprise me while I'm taking this on? Thanks for any tips! :biggulp

P.S. All I have is a good jack and an awesome set of tools.

Spokes

Simple job, only issue I foresee will be rusted flange bolts, and the screws / clip nuts on the surrounding tin which maybe rusted too. Start soaking the bolts and nuts with your favourite rust free product.

melman911

Will do!

Mike Murphy

There's nothing harder than rusted exhaust, unless you have a torch, in which case, be careful.

melman911

Thanks for the heads up

Porschenut_Lee

Rusted bolts can be handled with a small cut-off disc attached to a dremel. Just go slow and remove everything that needs to come out of the way to make the job easy. Don't forget to order a new square gasket and new set of bolts for the flange to flange connection. I also ordered a new donut gasket for the primary exhaust connection since the old one can have carbon buildup which needs to be soaked to get clean. A new gasket will ensure a nice tight fit. Get the old one clean and keep it as a spare. You also need a special socket for the O2 sensor so that the wire has a place to go. I made my own out of a cheap socket. Do a quick google search on it.

melman911

Thanks Lee. Didn't think to order a new donut gasket. I'll get one. How about the heat shield bolts. The two lower ones are not on.

mystert

Its very easy if you take the wheel off. You don't need a special socket for the O2 sensor. Unplug the electrical connector on the drivers side of the engine bay, pull the wire out and use a regular wrench. Once you have removed the heat shield on the heat exhangers, everything is right there. Just (4) bolts holding the cat on and one on the primary muffler clamp.


I can swap my straight pipe out for the cat in about 30min. No need to replace the exhaust donut on the muffler side either. Its a chunk of stainless steel and doesn't have any wear components. Just clean it off and reuse it. If anything I would replace the bolt in the clamp as they tend to bend when you crank them down tight. Also use a anti-seize on the threads of all the bolts. I prefer nickel based but that's me. You wont have to cut the bolts off next time you take it off. The hardest part of the job is aligning the aftermarket part to the primary muffler/cup pipe. They tend to not always line up perfectly and take some tweaking to seal.

melman911

Thanks! How hard is this? I noticed he bottom bolts are missing on the shield. The one that attach to the cat. Are there ones above it and how difficult are they to get to. I have just look under the car and cant see them. The cat comes in tomorrow so just trying to see what I;m going to be in for.

mystert

It's very simple. Once the wheel is off everything is right there in front of you. This is the heat shield. Use a 1/4 drive ratchet and a 10mm socket I think it is. The bolts just go into speednuts on the other side.

HoBoJoe

Get a can of PB blaster before attempting to loosen anything, spray all the bolts/nuts down and let it sit for a bit before attempting.

Also, like Eric said disconnect the electrical connection for the oxygen sensor instead of trying to unbolt it on the car.

Super90

Lots of good advise here.

One thing not yet mentioned, and maybe everyone is past the obvious, but please make sure you have some good jackstands under the car before you put yourself under the car....

If you car is from Texas or dry country, this will be far easier, but the penetrating oil is your friend. The connection for the O2 sensor is behind the blower motor on the drivers side of the engine bay. Remove the blower first.

Picture of sensor and connector:




It really is a one banana job, and getting the car on jackstands and the wheel off will take half the time. Then let the penetrating oil soak (PB Blaster, Kroil, Deep Creep, etc.), maybe even overnight if there is lots of corrosion. Then put the wrenches to it. It should all be pretty straightforward once you see it.

melman911

Thanks guys for all of the advice. Got me a can of PB Blaster. That's the oxygen sensor I got (Bosch).

cjoenck

Just to manage expectations. If the cat has not come out in a while and you don't live in Arizona, chances are the bolts are a solid rusty mess. I soaked them overnight but still broke two and had to grind the other two out. The speednuts are notoriously hard and I had to grind most of them out to get the heat shields off. Good news is that the Fabspeed cat does not need the heat shields - I believe - as the 100 cell cat will not get as hot as the OEM cat.
So all great advice above. Just prepare yourself for possibly some brute force "solution". You always wanted a grinder anyway, right?

Mike Murphy

Exactly. My 18-yr-old 996 had zero rust on the exhaust and quite frankly, still looked new. But most cars are not like this.