I have a 95 Toyota 4Runner V6 with approx. 128,000 miles on it and i have had no problems till now. The vehicle is hesitating between 10 mph to about 30 mph and it will not go any faster, then i start hearing this popping noise(like a back fire) in the air filter box but if you pump the gas pedal it will speed up and the noise stops but will kinda sputter a little while driving. It has not ever died or anything while stopped. It will idle great, but if you accelerate while in netrual the popping noise can be heard again in the air box. I have replaced air filter, wires, plugs and distributor cap plus the fuel filter. I have also cleaned out the cat. converter, but i still have that funny smell too. Could it be a MAF sensor, TP sensor, the O2 sensor or the fuel pump going bad???? Please I need help before i crash and burn!!!!!