can the epc light and the engine lightbe repaired by self

No it will have to be reset. Some times if a fault occurs and goes away the ecu keeps the trouble code. Depending on the type of fault the mapping will use a default, and usually uses more fuel and robs power.

I'm having the same issue. So far I've replaced spark plugs, coils, done a tune up, switched to premium gas and started using a can of cfoam per week. The problem continues.....

Stop the sea Foam!!