My 93 accord 5spd runs great for the first 10-15 miles, then it will all of a sudden hesitate badly and the check engine light comes on for the rest of the drive. It won't go over 3500 rpm's with the check engine light on. It is also very hard to start with the engine light on. After I get off work and start the drive home the same deal,, 10-15 miles is great then the same problems arise. I checked the codes and got 8 and 16. I am thinking the main relay might be the cause. Does anybody have any suggestions before I change the main relay? Thanks in advance for any and all help.