I have a 2001 Dodge Ram 1500 5.2 v8 that I bought back in march. I took it to get inspected last month and it failed they said I had 5 different codes pop up. So I looked into it and I have 4 different cylinders that are misfiring. I replaced all of the spark plugs, wires, distributor cap and Rotor (which were so rusty I don't think they were changed since 2001) and still nothing. The check engine light is still on and I have no idea what to do. My truck has 208000 miles.

 

What is the code, or codes? Need to know that.

 

With 200K you may have other problems. Was the plenum gasket replaced? Did you clear the codes? And it helps to post the coeds you are getting.

 

It looks like nothing has been done to the truck since 2001. so im not sure about the plenum gasket I have to check. The codes are P0128 (which I know that one is the thermostat). and P0300 P0302 P0305 P0307 P0308

 

Look up the spark plug wire TSB in the stickies. Did you get the regular, run-of-the-mill wires or did you get upgraded ones?

 

And what spark plugs did you install?

 

might test your coil

 

I bought platinum duralast plugs and duralast wires.

 

There is most of your miss fire problems, more than likely at least. These trucks only like the plain old copper core plugs.

 

Stick with OEM plugs for these trucks. They didn't come from the factory with those fancy (expensive) plugs and they don't like them.