E-ROC

88 p/u, 22re, 5spd. ive been searching and cant find a closely related thread, so here we go. in warm weather (70 and up) the cel does'nt appear, but as soon as the outside temp drops the cel starts up. heres the kicker. it only comes on when i decelerate but goes off right before i get to a complete stop. if i accelerate it stays off. when i try to jump the diagnostic pins (e1 & te1) it does'nt give any code. the tps is new and set correctly by my friend who is a toyota dealer mechanic and i have tried swapping my maf with my friends whos works fine and nothing made a difference. im losing my mind with this! any help is appreciated.