I would go to the dealer you bought it from - be really really nice - smile a bit and try to make them feel sorry for you - tell them you need somebody who can help you out - be somewhat humble - or maybe really humble - cry a bit ?? speak softly
The fact that you have a tune opts ford out of any warranty work - unless you have some sort of powertrain warranty in writing - and I do mean in writing - you are sol unless the dealer feels compassion for you.
I wouldn't go tearing anything apart or changing any oils until I spoke to the dealer - try the salesman who sold the car to you - ask him if there is anything he can do to help you out.
Good luck !
2009 Red C/S, 2014 Blue GT, 1969 Coupe 302