Key in ignition, tun to 'ON' position without starting truck. Then as slowly as possible depress the gas pedal all the way to the floor. Hold for a split second then release it as quickly as possible. Then turn key to off position. Repeat this process 3 times.
Then take the truck for about a 30 minute drive with mixed stop go and highway.
'04 XLT SCrew, 3.73 LS, KN Drop in, Custom Magnaflow SISO, 265/70/17 ATs, Westin Polished Steps, Leveled, Tonneau Cover