service engine light

i have a 2001 V6 mustang with 77K automatic. I got a P301 code(misfire number one cylinder). The car has a miss when it is under a load. I changed the plugs and wires it helped but not fully. Help would be appreciated.

Check for a vacuum leak close to the #1 cylinder. A too lean mixture on that cylinder will cause a misfire code, also. New plugs and wires will let it fire the lean mixture better, but that isn't the main problem. I tell just about everyone to replace their PCV valve and check all the hoses that it is connected to. It is a $3 part and if faulty can mimic a vacuum leak if it is stuck open and if it is plugged up it can cause pressure in the crankcase which will blow oil out past the seals.

I changed the PCV valve. I will check all the vacuum hoses attached to the PCV. I appreciate your help.