How many miles are on the durango? Change the spark plug first, back to champions. If that does't solve the problem. I'm going to say it once. Replace both cylinder heads. Thats because after about 70k miles on these motors, they start cracking at the valve seats. Causing a misfire at idle, but runs fine at freeway speeds. Before you install the new plugs. Do a dry compression test, the a wet compression test and then a running compression test. if you don't how to do any of these test, send me a pm. And post your compression test.

 

With a statement like this it's screaming TUNE UP with the correct parts. Simply put, you changed the plugs and wires and the problem got worse.

Go get some cheap Champion Copper spark plugs gap them at .040 then go to the dealer and get a new set of wires. Cap and rotor should be fine.

Next reset the PCM before you drive it: https://dodgeforum.com/forum/1st-gen...ine-light.html