I'm guessing you meant flushed tranny and not flashed tranny.
Would you say jolty as in quick and firm or jolty as in "feels like the engine is going to jump out of the engine compartment"?
You can check the TPS with a DMM. Backprobing the TPS with KOEO, the TPS should read less than 1v at idle and just under 5v at full throttle with a smooth increase in voltage as the pedal is depressed.
You can also check the MAF to make sure it is clean and plugged in/making a good connection.
The PCM calculates load based on several sensors including the MAF. Unplug it once and drive around the block, it should get very jerky.
Open the hood and have someone watch you change between N, D and R. The engine should not move more than an inch either way. If its moving around a lot then either the motor mounts are bad, the subframe bushings are bad or the subframe is loose.