M42 Probs.
 

So today my car started to buck really bad in first and second gear. It stalls if I turn the steering wheel kind of sharp, and at idle if I try to rev it up it sputters like crazy and shakes the whole car. 3rd through 5th seem fine. To drive it home I just rode the clutch real bad in first and second. It seems to idle okay until I give it some gas.

Bump

Mechanic's rule: look at the stuff you last "worked on", you may find yourself there again. No shame, we all learn this way, multiple times.

Check your intake hose elbow for cracks, also other hoses which could induce an unmetered air leak. Check the hoses to the idle air control valve, and the valve itself. Bimmers have a habit of clogging the IACV, and it needs to be cleaned.

Update: motor mount arm broke and ripped the intake elbow just as you said. Going to the junk yard Friday to get the arm.

Used mount arm okay, but get a new air intake elbow.

Already got one ;) new mounts as well.

Successfully retrieved the motor mount arm today. Tomorrow morning repairs commence.

Location: Honolulu, Hawaii whoa

Well, got the new intake hose boot, motor mounts, and that arm all installed. Car is much more solid now.

Those motor mounts can create quite a disturbance. Glad to hear you were able to sort it all out.