P0171 Toyota - with high idle

Question

97 sc toy previa p171 w high idle that is intermittent (turn off and restart minutes later and idle stays low until it runs for a while). MAF at idle 50 iat 70f (30f outside) atps at idle 11. egr seems ok haven't sensed any vac leaks. ECT 190f. ses light turns on after a lot of high idle time LTFT high 20's, STFT -4 to -8.

Answer 1

P0171 Fuel system lean

The long Fuel trim in the high 20's, the fuel filter could be clogged, the pressure can be good but the fuel volume can be low. this can also be caused by the MAF (mass airflow) intake boot having cracks and allowing false air.Take a close look at the fuel pressure regulator vacuum lines for any rupture and also a fuel pressure regulator leaking at the vacuum connection.going into the intake.