things that u can do
wd 40 all linkages,pull back the rubber and spray the stepper motor. mine has acted up several times and cleaning and also quick revs u might even work the throttle while not running taking it open and let it lose on return.
the tps can be checked with a volt meter but u have to pierce the wires or probe the connector if u have never done this i would not start now. like said the tunecu works great and i consider it a must have. i think it works better with the old lap tops some use it with there phones.