Cylinder 4 misfire

Even with new components, swap cylinder 4 items - one at a time - with an adjacent cylinder and recheck. If cylinder 4 still has an issue, perform a base engine compression test and leak down test. If that should be "normal" then you'll want to check to see if fuel is getting into each cylinder. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops