Ok, I took my pacifica through some sand and burned the wires between the wiring harness and the o2 sensor in the back. the car started jerking a lot after a couple weeks and acting like it was running out of gas. We changed out both o2 sensors and repaired wiring with piggy backs and dealer sensors, to the tune of 397 dollars. But we took the car home and it started doing the same thing. the strange thing is that it does it when you first start the car and take off, once you get to about 30-50 mph it starts acting like it's out of gas, but if you pop the car into neutral, turn it off and turn it back on, and put the car back into drive while going down the road, then it runs like a dream. the mechanic had said that he thought he smelled a bit of a sulfur smell, and wondered about the catalytic converter? but who knows. any suggestions.? plus it idles really rough after a couple minutes.