So last night, after struggling with a mysterious loss of coolant for a while now, I finally caught a drop coming from my water pump. A couple of days ago my service engine light came on for a few minutes and went back off, tried taking the car to O'Reillys and the guy said no codes to be found. Driving home the light comes on again, next time I start the car it's gone. I plan on having the computer scanned again because I'm not sure the guy did it right, hood sticker says its obd1 but guy said its obd2 connector.
From what I've read you need to manually enter vehicle info in this case but the guy wouldn't listen to me and got error, yet still managed to show me a "no DTC codes found" or something like that. So aside from checking again, does anyone know of a cause for the SES light that wouldn't throw a code? Could it in someway involve my leaky water pump?
Edit: current car is 95Z M6 bone stock.