I know this may have been asked before but here goes anyway. I have an o7 F150 SCREW 5.4L with Tp tunes and AF1 3" CAI. I tow a 26 foot travel trailer weighing about 4800lbs or so. When I tow even across relatively flat ground I get what has been described to me as the torque converter locking and unlocking. To me it feels like the truck is shifting alot between gears. This seems to happen weather I turn the OD off or not. You can see the RPM's moving back and forth on the Tach.

Does anyone know a solution for this ?

 

stop towing with it and call Mike Troyer asap. there was a post a while bakc about another guy having the same issue. I believe it was in the tune and Mike worked it out eventually.

 

can I still tow with it in stock ?

 

try it with the stock tune and see if it does the same thing since you have the 3" and not the 3 1/2" CAI you should not be running lean