Well Guy's I have a 2000 Dakota SLT quad cab and for the past three Months have been trying to figure out myself why the misfire. I have done Everything From a Compression check to swaping plug's, coil pack, and replacing injector and still no Luck. just yesterday I spent the day with the truck in my garage looking around for loose connections etc...
Just rebuilt this engine from top to bottom so there are no leaks whatsoever on the engine itself, no I did notice a faulty power steering line leaking quite a bit of fluid and noticed this fluid soaking up my Wiring harness. I baught brake and electric contact cleaner and cleaned the harness and repaired the leak, I let the truck sit overnight, today being sunday I walked into the garage, turned the Key and the truck Idled Fine.
Drove it around for about 200 Miles and No longer had a P0303 Code, No misfire. I think I found my problem Folks.

 

i popped the p0303 today misfire in cyl 3... i havnt even started to check out the situation yet but i do know that my ps rack is leaking a bit so ill head there first.. thanks for the info.

ps.. what did you use to repair the leak?

 

On the 4.7 it's usually a bad power steering pressure switch.