i changed spark plugs,coils and catalic converter at 200000 miles i had a guy that works as mechanic at ford dealer shop he wanted to charge me almost 3000 bucks for work on a side dealership want it 4500 i bought spark plugs after market that are better than the one u can get at dealership for about 5 bucks cheaper for each so instead off payin 18 for each i paid 13 bucks. coils are like over hundo for each i paid 30 for each and ford mechanic told me coils are less to worry about. than catalic converter at dealership is around 1500 i got it for 500 after market and 2 year warranty on it. truck runs great i love it but there is one more problem that is not cheap. i forgot what it is but im not worried about it. lots of ppl told me this car can run forever