ecu light?

hi,the problem i have is engine management light on its been diagnosed as maf and iat sensors my mechanic has checked all wiring for faults none found he has said it is the ecu itself that is faulty ,he has quoted me 600 to replace it, the problem i have is the car is running great no problems at all just the light on the dash ,can i cause any damage to other parts if i just ignore it ,i mean it seems daft to pay 600 quid just because the ecu light is on isnt it!!!!