please help 99 explorer acting up again..

[IDNTH8T]

ive gota 99 explorer xls 4.0 ohv thats running rough at idle. the check engine light came on i think the code was po303 it said misefirein #3 cylinder. has anyone had this problem before if so how did they fix it all help appreciated. thanks... :roll:

 

[south59]

Check the condition of the spark plug and wire that runs to that cylinder.

 

[MCDavis]

I had the same thing, but had to take mine to the dealer, 8 new plugs and wires, not even going to tell you how much, sad day. But couldn't reach the last two plugs myself without removing more than i wanted to. Sucks living downtown with no where to do real work.

 

[IDNTH8T]

could it be the coil pak? "o" rings from intake? or carbon build up on the valves? my x has 111,000 miles.

 

[badgett]

If it is pretty bad at idle and fine on the road it could be the throttle position sensor. Happen to me.