I haven't touched the engine since I bought the boat last spring. Just been adding some injector cleaner and burning the spensive gas. Maybe I'm running on 7 rather than 8. I guess I'll buy a set of plugs. That would be a pretty cheap fix.. I am having the local boat repair shop run the codes next week. Problem is, there is a lot of boating time between now and next week. Thanks for the lead Tuneupman!!