I've had my subaru about 3 years, only has 77,000 miles on it and is regularly serviced. Today my Check Engine light came on. The car is running fine. Any suggestions?

Too many possibilities, scan test required.. That's about the mileage Subarus start giving trouble, as noted @ the shop.. Various problems from head gasket failure to oil leakes plus electrical component issues.. Good luck with 'your' vehicle..