2001 Ford F-150 engine miss

If you did replace the plugs as well, then look into faulty emissoin system components, cracked distributer cap-if equiped, weak or faulty coil(s), vacuum leak at intake minifold or plenum or vacuum hoses. Have you gone to advanced to see if you have any codes?

Replaced plugs roughly 20,000 miles ago. No check light or codes thrown. Will replace plugs and go from there. Thanks for your responses!

No thats not it. Plugs onley need replaced every 30k. Have you had a loss of power. Here are some more things to check, but i'm not sure about them either (ignore number 7) Engine lacks power. See one of the following: 1.) Incorrect ignition timing. 2) Fuel filter clogged and/of impurities in fuel 3) Faulty or incorrect gapped spark plugs. 4) Air filter dirty. 5) Spark timing control system not working properly. 6) Faulty ignition coil(s) 7) Brakes binding. 8) Auto Trans fluid not correct 9) faulty distributor cap or wires 10) EGR system not functioning properly. 11) Use of sub standard fuel. 12) Low or uneven cylinder compression pressures 13) Air vacuum leak at intake manifold or plenum