ok i bought a 1999 mazda 626 and had trans replaced i got it back and i noticed that the mas air flow sensor was diconec and the haness had been modified some how and the wires were touchin with out thinkin i pluged it bak in and moved wires apart well the wires touched some how and smoked does that mean i need to get a new ecu or is there a relay that goes through there are a fuse are somthing ?????????????????? and the car will sTART AND RUN IF THE SENSOR IS DISCONECTED BUT IF YOU PLUG IT IN THE CAR DIES THE CODE READER READES MASS AIR FLOW SENSOR LOW INPUT AND I REPLACED BOTH SENSORS ON THE AIR INTAKE IF I NEED TO GET ANOTHER ECU I WILL AND I NEED TO KNOW IF I CAN PULL ONE OFF ANOTHER 626 WITH MATCHING NUMBERS YOUR HELP IS APPREACIATED

 

Sounds like somebody's been fiddling with the elecs to get around the air metre fault, i'm not a sparky but you can certainly put another ECU in as long as it has the same part number.

Sorry i can't help further, good luck with it.