Bear gave some good advise with only one mistake. Replacing injectors costs a lot more than that. From the dealer I'm gonna guess the injectors are well over $100 each just for the part. Then the labor to install them, forget it.
There is a thread going on at the other site and it seems there are a lot of guys experimenting with MMO in oil and gas and posting some good positive comments about it. It is in the gas additive section IIRC. MMO has plenty of valve with older engines and Ethanol gas. FWIW.