I have 190k miles on my 2003 Supercrew 5.4l. Recently the milage has dropped off from about 350 miles per tank to about 300. Is it time for a tune up? What is worth replacing and what is not. I just replaced the fuel pump and filter a couple months ago.

 

Plugs, air filter, clean throttle body , clean iac, clean mass air flow sensor, maybe put and injector cleaner in the fuel