My buddy with a Duramax had to replace all his injectors at 120,000 miles and got me worried - I have about 200,000 miles on my 2006 Dodge. How long do injectors typically last and how does it diff...
The halo test works also. On a clean paper towel drip hot oil from the dipstick and wait a little bit. If there is raw fuel in the oil it will separate into an outer ring that looks like a halo. If your oil level is increasing that's another indication of at least one bad injector. Replace them all, will run about $3K. You are in the target mileage. (so am I)