Hey guys, new here.
My truck runs pretty good nost of the time. Lately having an issue with it not wanting to shift from 1st to 2nd. Especially going up a hill. Its the 4.3l 4l60e. My brother and I changed the solenoids and computer thing and put a valve thing in it. Not alot of change. I saw where others look at the mass air flow and throttle position sensors, and was wondering if that my apply in my case? Any info would be greatly appreciated.