You don't have to update the program on your pcm but I'd recommend you ask a dealership to see if there is an update before you get a tune. That way you have the latest and greatest from ford as a base for the tune to work off of.
Use your xcal to datalog the problem. Log TPS, all 4 fuel trims, loop state, MAF voltage, o2 voltage, IAT sensor, spark, and load. Then post back the results. Every other post on here is just a guess. Get the datalog info and we can point you in the right direction.
Use your xcal to datalog the problem. Log TPS, all 4 fuel trims, loop state, MAF voltage, o2 voltage, IAT sensor, spark, and load. Then post back the results. Every other post on here is just a guess. Get the datalog info and we can point you in the right direction.