Cowart Tractor

Looking for someone who can possibly tune the ecm so that I dont have a light.

I recently purchased an 05 Mack ch613 with the 427. Runs great. Fuel economy towing my equipment seems a little low. Average of 5.3mpg. Has a check engine light for egr mass flow sensor. Assuming egr not acting properly is affecting fuel economy. Was wondering which direction yall are going about making that side of the engine a little lighter, if you catch my drift.