want to know more about fault code 2637

[DVT873]

OK, face plugged on the DOC again. DPF filling also. less than 30 hrs on DPF. Doc was vacuumed out when DPF was replaced. On the stand the DOC was 4.2 inches of H2O and DPF was 3.2 inches. DOC cleaned down to 2.2 and DPF to 2.2. Soot was dense and just a touch damp.

This was a flatbed before the current owner bought it and made it into a dump. I suspect that it ran a lot of highway based on miles vs hrs. That may have kept the exhaust just hot enough that this problem was masked. Cummins says greater than 550F in the DPF will help keep it clean.

Have done the EGR tuneup including EGR valve replacement. Get just a whiff of fuel smell when running w/o the cans on but hardly any smoke except on snap accel. 10,140 hrs. 316,642 miles. I'm thinking injectors. I can get them tested. I hate replacing stuff w/o knowing for sure what is going on. With injectors out will do a cyl leakdown test. Will also run rack while we are there.

Open to suggestions. Pics attached. There IS NOT coolant staining, light could have been better. Should have stayed on as Peter Gowlands set assistant and learned more about photography.