I still don't know what happened. But tonite departing SAN in my C340 (Carenado model), in XP11pb9, I was assigned a 310 heading... Well I could not maintain even runway heading at first. I couldn't bank right! I know it was busy so I told lindberg tower right away but initially I stepped on someone. Then I said it again and declared emergency - tower asked what I wanted to do and maybe offered a suggestion which I totally missed... I basically was able to make left turns so the best plan of action was to make left closed back to 27. Funny thing is (thankfully it's just a sim), I almost crashed completely because I wasn't climbing well at all initially. I forgot to raise my gear! Doh! Figured that out just before I hit vmc (not weather, the red line on the airspeed indicator)... so in a climb setup sort of in a left bank at high angle of attack, I was definitely nearing stall conditions. Grrrrr. Still I think I handled it ok once I figured the to raise the gear.
I've checked everything on my aircraft. AP was off, trim was centered, the yoke was moving freely, both engines operating normally, no needles dropped off. No clue

Anyway, I live to fly another virtual day! Special shout out to PG for helping me out

P.S. In case anyone is wondering my first serious emergency was when I applied Full Rental Power (KS's wording lol) in a Piaggio P180 during takeoff and climbout... then experienced total engine failure which actually ended in a safe 180 teardrop back to departure airport.