Iv'e got an '02 Durango with a 4.7L and 80,000 miles. Now and then the engine seems to accelerate or surge periodically when at cruising speed on the highway. No check engine light or anything comes on and otherwise it runs and idles like a dream. I don't believe it is in the tranny, it just feels like your increasing speed for just a split second the rpm's go up a little then back to normal. Just looking for some educated opinions on what I should be looking at. Thanks for any help....

Throttle Position Sensor, you can take it out and try cleaning it. If it still does it, get a new one, but don't buy a cheap POS from Autozone or any where like that.