Toyota Repair: full accelleration misfire/stall, accelleration, new spark

Question
I have a 1999 4runner V6, auto, . The car runs fine until I floor it, like passing on the highway, then it will misfire and stall when it shifts to higher gear. When I back off on the pedal, it runs good. Any thoughts on this?

Answer
Try doing a major tune up which should include new spark plugs, distributor cap and rotor, plug wires and an air and fuel filter. Let me know if you have replaced any parts recently or any work that may have been done at a repair shop and also when this problem started.