Ok so I recently drilled the wheep hole and then programmed my 2013 f150 EB with the SCT X4 (regular 87 octane tune) and it has been running great for about 2 weeks (Not sure if this has anything to do with this issue). Yesterday I drove about an hour away and on my commute back I noticed the truck was not getting warm with the temp on 74. I also noticed my compressor was very loud and was running very loud since I started my engine. I turned the temp up and noticed when I would accelerate the heater would work but when I would let off the gas pedal cold air would come back through the vents. it has done this the past day since I noticed. Not sure why this is happening any thought?