Mass air flow sensor

Mechanic replaced part TWICE, rebuilt, it worked for hour, then back to same bad fuel mileage and rough running. Dealer says car needs OEM equipment or it won’t work right, mechanic says bull, who is right? when mechanic hooked up hand held meter, said mass air flow sensor, and right and left fuel bank problem

Please get the codes from the mechanic. We have our own decoder rings. The codes inform a mechanic about the conditions in the circuitry which the sensor is a part of. The codes do NOT say a particular part is bad. It talks about the SIGNAL in that circuit. BIG difference.