Well I called the dealer today and questioned them about replacing my plugs. I have a 04 F150 FX4 with 35000KHM and asked them if I should change them. Ford says not to change for 100,000Ks but he said if you want to keep the truck change them now, that it will only be a bigger problem later on. So I make the appointment for Tuesday next week the charge is $211 Canadian this includes a tune up. The plugs are $13 ea. So my question is how long till I need to change the plugs again, I know ford has a plug problem but by the time the dust settles I am sure it will be a $400 bill. So what are the rest of you doing change them every year or what????????