Miss firing under load and RPM, 02 w/8.1
 

I am having some issues with my 02 w/ 8.1 missing under load at 3k to 4k RPM. Code reader says P101 which translates to MAF sensor. (mass air flow sensor) I cleaned it with a CRC product made specifally for that purpose, but didn't seem to do much good. ( it was very dirty) No other codes showed up during test drive. I have just turned over 100K and it has been an outstanding trouble free 5th wheel tow truck. 22000 lbs about 50K miles, and no trouble till now. Love that Allision. I plan to keep it to the end. ( me or the truck, whichever quits first) I have replaced the obvious things like spark plugs, fuel filter, air cleaner. I suspect the problem is in the fuel system as opposed to the ignition. Does anyone have any sugestions??????????