I recently bought a truck to pull campers with. Put a $5k flatbed on, bumper, 150 gallon fuel tank and about 800 pounds of tools. Truck is a cclb dually with a duramax. It’s heavy. So, as a result, it was very slow and had a lot of trouble getting itself and 17000 pound campers up to speed. Then I started getting pissed off at the thing overheating, so I removed the EGR. In doing so, I broke the Y bridge in some way. Way less power, blowing black. Took it to the shop, got a new y-bridge, turbocharger and air filter. Truck had more power, but still blows black and isn’t returned to stock, and I have a 5500 dollar bill at the shop I can’t pay. Any suggestions at what it might be?