Last night I went out and drove the truck and it drove great shifted awsome. Got on it a few times and it shifted fine. Went out this morning and on my way to work realized it prematurely shifts and luggs the engine down. The CEL flickered a couple times. It never idled down or died just prematurely shifted. Once on the highway it shifted fine and downshifts fine. Got off the highway and it shifted fine for like one light then started doing it again.... Tuning?TPS?MAP? some sort of pressure issue? Thanks.