First thing would be to get the cause of the check engine light. You can get the OBD2 codes or, as most members here have, is a cheap laptop with INPA installed and a diagnostic cable.
When I put my intake manifold back on after decarboning the intake valves a couple months back, I had a hard time starting the car back up since I had opened the butterfly valves on the throttle bodies. I ended up resetting the throttle bodies with the pedal procedure and it started back up, a little lumpy at first, but it smoothed out; might be a quick fix to your issue.
If I were you, I'd also get a look at the intake valves to see how bad they have carboned up. The direct injection on the N73 is different than the port fuel injection on the M73 which may be contributing to your idle issues by leaving PCV deposits on the back of the intake valves. Does the car stall only at idle or during 2000 RPM+ driving?
Last edited by new760Liowner; 11-12-2012 at 01:30 PM.