Fuel delivery Ghost.

2002, toyota, tacoma pre-runner double cab, 140k miles and v6 with KnN cold air intake system upgrade.

today I put about 10 gallons of gas from a Shell station in my truck. In my 40 mile commute to work, my truck stalled aprox 15 times. The stalls occured when I would let off the throttle. Even while on the freeway and simply removing my foot from the gas to step on the brake (automatic trans) so, on the return home, I had to drive the same way, either the engine under load at a stop, or in N with the revs above 2K. Spontaniously, this afternoon, the problem STOPPED and has not occured since.

i put the engine thru all sorts of load testing after the probem stopped, none recreated the fuel delivery problem.

looking for possible causes and or solutions.