P0171 Ford - 2007 taurus

Question

Engine light comes on. Reset and comes back on a week or so later. Code 171, system too lean, Bank 1. No surging or running badly. Gas mileage same as before. Help!?!?

Answer 1

Hi there,

This is usually a problem with either an intake manifold leak, or the bank 1 O2 sensor 1 before the converter. This would cause a lean mix on a single bank but the engine would seem to perform normally.