sorry to resurrect the thread but i ave the same thing, it is in the are of the brake booster and it is clipped to the oil dipstick guide tube for routing purposes and about 3 inches up from ther it forms a u bend back down then terminates with no conncetion in sight, please help guys, i ahve a p0171 and p0174 and oil dipstick vacuum test seems good becuase when i remove it i get strong suction. thanks