I have a 2007 fx2 5.4 vin code 5 it started miss firing at 150,000 miles been putting off the plug change.. finely it started loosing power so changed plugs checked out all coils replaced plug boots and springs and fuel filter. Truck starts and idles fine hitting on all 8 test drove took off just fine at first then started bogging down . eased up on throttle run pretty smooth drove aprox 5 miles started loosing power and back firing a little bit by the time i got back to the house it would hardly pull in the drive way was thinking maybe fuel pump have not ran a compression test as of yet just sunk about $400 in plugs and tools to get them out didnt see a test port for fuel press any ideals on how to test fuel press and what are the specs