You need the graphing tool to decipher the txt file. Only some dealers get this info. If you are not at a dealer the data is essentially useless you. Here is the "cowboy" way to do it. Remove the 4 bolt flange and disconnect the DPR from the exhaust. Bring the engine up to temp (176 degrees or higher) Turn off all loads, lights A/C ect. Run the truck for 3 min at 1500rpm and recoded the injection quantity, then let the truck idle for 1 min then record the injection quantity. if the injection quantity is higher t idle then at 1500 your injectors are overfueling. You should inject LESS fuel at idle than at 1500rpm. like I said this can give you an indication but is not the preferred way to do it.