I am in need of new injectors for my 03 Durmax 2500 with 118,000 miles. Last owner had rebuilt ones installed for 3,000 at 96,000 miles. Now I need new ones and it will be $5800 with new CAT filter and Napa Injectors. Is this right??? Holy Smokes (pun intended). Truck does not smoke YET, but we need to tow our 5th wheel in a week! HELP!