my check engine light came on and i retrieved a code p0171.i have a 2000 prerunner with a v6 and automatic.105,000 miles.bought it used and it had 93,000 on it.i had the timing belt,pulleys,waterpump,thermostat ect. replaced right after i bought it,i also put a k&n airfilter in about 4000 miles ago and was reading about that and some of its problems in here.i cleared the code and the light hasnt come on but its only been a day,i know things dont fix themselves.any ideas,thanks