odd truck problems tonight
ok, so recently i had a CEL come on, tonight i was in town and it just went away. so im taking a friend out to about 10-12 miles out of town, where there are a lot of hills and stuff. the first steep hill im doin 55 in 5th, so when i hit about 52 i go down to 4th. then all of a sudden the truck starts jerking back and forth and the shifter feels bumpy as hell. i get over the hill and go back to 55. a little later were going to another place, and after a small *** hill my CEL starts blinking, and stays on. so later we go back to town, it happens 3 more times.
any idea on whats causing this?