SO, when you buy one from some place like CARiD, you can order a custom tune when you buy it? Or do you do that after you have it in hand? I know nothing about tuners. I really want to get a 93 octane tune so I can run it without the damn misfire CEL setting. As it is now, any time I put in 93, I get a misfire CEL. I put two gallons in a full tank the other day and within 40 miles, went from no codes to a P0300 and P0302. Put 3 gallons of 87 in it yesterday, cleared the codes, and they've stayed cleared. It's a real head-scratcher. Only thing I can think of is the 93 has an excessive amount of methanol in it. But, my Lightning and tuned up V6 Ranger do fine on it.