I retired in 2015 and bought a 2015 ED Outdoorsman. I live for the outdoors (hunting, fishing, camping, hiking)and the truck is perfect for the task. I like it but have concerns on problems that may come about when it is out of warranty. Bought a bumper to bumper warranty extension to the 100K. The warranty is over in 6K. I have had to replaced a front hub, DEF freeze up, fuel rail / sensor, changed to Rotella T6 @ 66K, and at and multiple computer upgrades. I now am loosing coolant. Have looked at youtube and seen a video on the Egr cooler. How do I determine if it is the EGR cooler leak. If is what do? I have also seen a video on full DPF delete, would this solve the problem or is this to extreme. I am planning on purchasing the Hot Tune GDE Tune. Do any of you use fuel additives, if so what are your thoughts on what is best.