i have a 2004 explorer with the 4.0,every now and then when your driving in od under 2500rpm the truck has what feels to be a slight missfire,if you give it gas when this happens it clears up and runs fine,now it has died on my wife a few times when she is slowing down but will start right up with no issuses,it runs fine untill it just shuts off and after you re-start it.im wondering if the coil pack could be on its way out,the truck has 135,000 on it.it doesnt do these thing constantly,just when it wants to.any help would be great.

 

Let's start with the basics, when was the last time it had a tune up consisting of at least spark plugs, plug wires, air filter, and fuel filter? Have you checked the throttle body for signs of significant carbon? Does it idle fine when first started?

-Rod

 

its been about 20,000 miles since i did all that,it starts up perfectly fine and runs the same.im still knocking down 19mpg on the freeway