[Rmtt]

[QUOTE=rowsdower;25001440]Was this originally a California/SULEV car? If so, it already has the N51 motor with the 3 stage intake. If not, I doubt adding the intake to an N52 will cause smog issues. I am sure you're not the first to do this. Search here and E90Post to see what others' experience with CA emissions has been.

I took mine off recently to check for play in the DISA valves. I replaced the intake manifold gaskets, the throttle body gasket, and the crankcase breather hose. The breather hose is brittle and tends to break so it is good to have a replacement ready before tearing out the intake.

Bimmer Performance Center (BPC) generally is regarded as the best off the shelf tune.[/QUOTE]

They are no longer in the tuning business.

OP....check my sig for recommendations.

Everything rowsdower mentioned is what I did and would do. I went ahead and replaced my DISA's with ones from FCP as they have a lifetime warranty.