I think you can use this:
http://www.ardesign.info/store/bmw-1...el-fix-v3.html
to deal with the CEL if you go with straight pipes. Tempted to get the AR downpipes and cats, now that Cobb has a map for that.

 

yeah id go with ar's downpipes if their stuff wasnt super mega expensive haha
but i am thinking of getting rid of the mid cat and run a straight pipe. i hope cobb can delete the CEL light

 

ok guys thank for all your help I ended up getting the cobb, aFes DCI, AR design downpipes (catless), UMNITZA's quad exhaust and took out my secondary cat running a straight pipe. I have not installed the dci and DP's yet but alone without the secondary cat and the quad exhaust i can get into the high rpm now. before short shifting around 56-6000 would be where I was shifting for optimum power now I can let the car go up to redline before the car automatically shifts it. also now that I have cobbs stage 1 aggressive with linear throttle map the thing really flies. I cant wait to install everything else and run stage 2!!!!

 

Post some pics bro