re: 2009 F250?

If you look under the truck by the passenger front door there is a huge filter that is your DPF filter, every now and then while driving you will notice your truck will go into regen mode which is when it is cleaning out the filter, also you have 3 sensors on top of it, i had one go out i think it was my EGT sensor and it left me stranded on side the road and i had to wait for the truck to completely cool off to hurry my arse to the nearest exit and gas station, luckily i had just stopped and bought the sensor before it happen and had to change it in the parking lot of an exxon lol