Engine Mechanical problem
1997 Dodge Caravan 6 cyl Front Wheel Drive Automatic 165625 miles

Van stopped running we were told it was spark plugs and wires. We were able to change all but one plug. Engine starts now but while driving it starts to stall and hitting the gas won't make it pick up speed. While it's idling, the engine sounds like it's running hard and the headlights go dim. Once we get to about 45 mph that's when it will start to slow down by itself and sometimes the engine will just cut off. The one spark plug in the back is impossible to reach, we changed the wire but could that be the problem?

If it is the one the back close to the passenger side, then yes. It is your #1 spark plug. The PCM uses #1 spark plug for timing, fuel delivery and a whole lot of other stuff. If that plug is bad, the whole motor won't run smoothly.

Also, you have OBD-II compliant PCM. Take it doen to Autozone or Checker O'Reilly and have them scan the computer. COme back with the fault code(s).

Yes it is the one back close to the passenger side. For some reason my husband can't get it off. He's tried different tools, took the windshield wiper part off but he still can't get to it. Any suggestions?

And thank you so much for your input