I bought my 2003 Dakota about 5 months ago and I have never been impressed with the power of the 3.9 V6. I have the 2wd extended cab, 6 cyl with 172,000 miles. I changed the plugs a few weeks ago and got some power back. The plugs were not in bad shape but one of them was not even finger tight. The crush washer looked new. I decided yesterday to change the plug wires, cap, and rotor. I have posted a pic of the rotor. I don't know how it even ran but she runs like a champ now. I wish I could get a good pic of the inside of the cap. It is just as bad. I am positive the wires, cap, and rotor were original equipment. The moral of the story is if you buy a used vehicle, don't assume the PO took care of it as good as you will. By the way, I went from a Ram to the Dakota and love this little truck even with the high mileage.

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Changing the cap, rotor, coil, and wires was one of the first things that I did on my truck.