ANYONE KNOWN HOW TO CHECK A COP THE IS MISFIRING. I,VE CHANGE THE PLUG TWICE AND KEEP GETTING THE CODE PO303. THANKS FOR ANY ADVISE. 2000 F150 5.4

 

You can use an ohm meter to check the resistance. Between the two coil terminals (primary) it should read 0.55ohms, between one of the terminals and the end that plugs on the spark plug (secondary) it should read about 5,500ohms.

 

You also should check your injector pulse width as well as listen for the injector tapping while runing. The easy way to test the COP is to unbolt it and stick a spare spark plug in it.