Air Mass Sensor

I RECENTLY HAD THE AIR MASS SENSOR REPLACED IN MY 1992 525i...NOW I'M NOT GETTING THE SAME GAS MILEAGE...WITH GAS PRICES SOARING, I'D LIKE TO KNOW IF THERE'S A CONNECTION OR ANY RECOMMENDATIONS IF NOT RELATED TO THE AIR MASS SENSOR...

Hmmm, was the Air Mass Sensor replaced with the BMW OEM part, or was this an aftermarket part you has installed? Was the sensor itself replaced, or the whole Air Flow Meter (the unit just behind the air filter)? Does the car drive any different than before, or does it just get worse gas milage? Was the air filter changed as well?
Sorry for all the questions but it might help to figure out whats wrong. I once neglected to reattach the AFM sensor wire and tried to drive my car, which pretty didn't work right, and took me a few hours to figure out my simple mistake.

THANK YOU SO MUCH FOR YOUR RESPONSE. I DID HAVE AN OIL CHANGE THAT DAY AS WELL. THE AIR MASS SENSOR ITSELF WAS REPLACED...A BMW PART, NOT AN AFTERMARKET PART. (HOW COULD I TELL...IT DOES LOOK DIFFERENT FROM THE PREVIOUS ONE) THE CAR RUNS AND RIDES SOMEWHAT BETTER...JUST HATE THE GAS MILEAGE...I'M ASSUMING HE CHANGED THE AIR FILTER WHEN I HAD THE OIL CHANGE...ISN'T THAT AUTOMATIC? I GUESS I SHOULD ASK THE MECHANIC.

THANK YOU AGAIN

aren't air sensors adjustable? maybe it nees to be tuned