Might even be a bent rim. Had the same issue on my FT TC4 RCGT car. Totally erratic behavior, pulled to the left, traction roll, you name it.
I didn't find the problem until i put the car on a stand and ran the throttle at low speed. Right rear was wobbling so bad the whole stand rotated to the left.
So when all else fails, check your wheels!!
A couple weeks ago I switched my VTA from my S2S to a Cyclone TC. While trying to get a good race setup on the Cyclone my car would push on/off power on left turns and would be very loose on power on right turns. I tried everything I could to get the problem to go away, different springs, lower roll center, bearings. I went back through the basic setup and corrected a couple very minor setup issues, front camber was off by .5* and re aligned the steering. I even swapped shocks side to side just to eliminate those. Nothing that I did would correct the problem. That is until I swapped tires side to side then it did the opposite of what I started with, push right and loose left. So it seems that I have a bad tire or insert on my car. I am not worried about which tire is bad because I have a new set of tire glued up and ready to go. I was just trying to wait to use them until we started to race.