Stuttering and dieing at 2-3k

[Ronin]

I hadn't moved the car for around a week, it got buried in snow while I was away for a few days and yesterday when I tried to start it it turned over sparked but did not start traced the fault down to the plug had come lose from the ecu. Now when I drive the engine stutters and feels like it's going to die between 2-3k revs, and I have to rev the nuts off it and slp the clutch driving round town to keep it going.
Anyone have any ideas?