I have a 98 GMC... orig a 305 but it was swapped with a carbed 350 and a B&M Throttle Position Sensor to talk to the computer/tranny. It runs, drives, and shifts perfectly for flat ground and not getting into it.
Under load, like hard pedal or while climbing a hill, it seems like the overdrive is acting weird shifting up and down... not sure if it is in conjunction with the shifting but my gauges tend to bounce around at the same time.
I have a lot of codes for things that arent hooked up but specifically, I do get P0122 GEN TPS LOW Circuit Input.
It has done this since I got the truck soon after the swap... one of the issues the PO never worked out.
Could this be the problem? What can I check to find out why I am getting that code? Could it be the TPS is bad?