Possible bad accelerator pedal position sensor?

I had my throttle body cleaned recently (one person was pushing on gas pedal while the other cleaned throttle body with throttle body cleaner). Right after that, I drove it and noticed the idle was all over the place and the gas pedal would stay down (like it was in cruise control). I had to have a used transmission put in (bad idea to take it to the dealership - pretty sure they burned out 1st gear) but I'm worried that I'll still have the idle/gas pedal problem. I'm just wondering if this would be a bad accelerator pedal position sensor (I don't have a TPS) due to the gas pedal being pressed down so long while the TB was being cleaned. I ordered an APPS but my car is still at the transmission shop. They said they'd try to diagnose my issue after replacing the transmission but wanted to get a good grasp on what the likely issue is.