P0171 1999 FORD WINDSTAR -

Question

i have a2005 ford 500 ,3.0 engine check enginelight on have replaced upper manifold,egr valve,tube and connector,ford dealer suggested replacing the brake booster,02 sensors,pcv valve,ford dealer can not find the peroblem,had the car 4 days,any suggestionsofie

Answer 1

Hi there,

With all that you have done with this vehicle I would do a leak down test on the bank 1 cylinders. If there is a sticky valve or a valve with some carbon built on it, then it could cause the lean fuel mixture code.