I have about 85,000 miles on my Dodge Grand Caravan Sport with the 3.8L engine. I changed the spark plugs and wires about a week ago. After I replaced them, the vehicle ran great. Now, one week later, I am getting a misfire on cylinder 3 and 6. Any idea what might be causing it? Or how to diagnose it? Thanks in advance....

 

Did you replace the spark plug wires too?

 

looks like he did replace the wires.

This is where I'd connect an scanner and read misfire and/or a scope to read ignition pattern

 

Sorry........ I would ck the wires for a good connection. And recheck the gap on the spark plugs and maybe do a compression test on the number 3 and 6 cylinders.

 

The problem ended up being a bad wire in a wiring harness causing the misfire. In case anyone was interested........

 

what wire?

it's sure nice to know when the problem is solved. most users demand an answer in a panic then never get back to what the solution was.

 

Same issue. Can you tell me how much of the wiring harness you replaced?