I've own four cummins. 91.5 and 92 will run forever. They are just noisy and you have to deal with a 72 designed body. My 05 had a couple of weak injectors at 105k so I replaced them all and added a fast pump/filter system on it. I added a dealer approved power adder module on it at 50,000 and I think that hurt my injectors. It went out at about 90k so I pulled it off. With old injectors and the stock filter and lift pump, you are living on borrowed time. When injectors go out they flood the motor with fuel and do what they Rhino described. You have the same injectors on the 07. If it were mine I would put all NEW Bosch injectors and the fast fuel/filter system on it now before it craps out. My 2012 only has 23,000 miles on it with no problems. It has the most power and runs the best.