I have never owned a TT. This was a on a Carrera. I would not expect cat-bypass pipes cause you to lose torque at lower rpms on a TT as the turbos will always provide some amount of back pressure.

Check your code first to make sure it is an O2 sensor code. You have 200 cell cats on that exhaust, so you should be getting a CL from the cats. It does sometimes happen with 100 cell cats. If so, check the connections for the O2 sensors in the engine compartment and the wires to the connectors. Make sure your O2 sensors got installed be in the right locations. There are 4: 2 pre-cat and 2 post-cat. There is enough cable length to install them in the wrong locations.

L

You said on a prior Rennlist forum that when you put a cat bypass on your TT that your TT lost back pressure and power at low rpms ? I installed a Maxspeed Motorsports Performance Exhaust system on my '03 996 TT (non-X50 version). The check engine light has gone off since I installed the 70mm exhaust system with headers. I've changed the O2 sensors and even installed O2 spacers, but the check engine light keeps going off. I believe it is the Cats that keep setting off the check engine light, so I was thinking of going with a cat bypass to solve my check engine light problem.

Any thoughts ? I ask you, as it sounds like you have been down this road with your TT. I'd greatly appreciate any of your input or guidance. JIM - Nyse003@aol.com

First, unless you are going to run Hoosiers you are going to find you won't need 3 degrees of camber. With MPSCs and R888s, my car was optimal around -2.2 front and -1.9 rear with equal temps inside and out. Corsas need even less camber. Personally, I would just start with the GT3 control arms and see what you get with shims as I don't see also needing camber plates. I used a 10mm shim pack and could get about -2.5 out of it. This also increases the track about an inch, so turn in is crisper.

You need to run the control arms RSR style whenever you run a large shim pack due to caster gain and clearance. If not, your caster will be very high at over 8 degrees, you will be rubbing your fender liner when turning and your track arms will bind up when turning hard. Only run right on the right and left on the left if you are not look for as much camber gain/track gain from the control arms such as running camber plates with a 4mm shim pack.

Regards,

Loren

I read your comments about the GT3 lower control arms. I'm considering putting these LCA on my '06 Cayman S. I participate in DE events and run Hoosiers on my car.
I have a pair of Tarett camber plates that I used on an '03 Boxster. Tarett says they'll fit on the struts of the Cayman.
I'd like to get 3 deg of neg camber. Do you know if its a good idea to use the camber plates with the GT 3 LCA or should I use the LCA alone?
Why do you recommend mounting the arms RSR style? What are the advantages over mounting the right arm on the right and the left arm on the left?
Thanks for your help.
ahmeltzer