P0174 Chevrolet - 2004 chevy tahoe also have p0171

Question

my diagnostic codes are p0171, p0174, p0496. What would cause these codes

Answer 1

Hi there,

The P0171 and 174 codes are for a lean fuel mixture condition. When you have both codes it's usually a result of a bad mass air flow sensor or weak fuel pump. The P0496 code is for a faulty vent control solenoid on the evap system. Usually the vent control valve is the problem.