CM 871 Code 2639, DPF won't clean

[Rawze]

(03-06-2019 )Doops22 Wrote:  I started on the egr tuneup and noticed traces of antifreeze in the egr tube/intake pipe so it looks like I’ll be doing an egr cooler. I also noticed inside the head around the intake valves are wet. This one is worse than the rest. Normal or do I have injector oissues too?

make sure the "wetness" is coolant and not condensation. ISX is notorious for getting condensation in egr and intake circuits.

Test EGR cooler by pressurizing the coolant system over night to 20-psi and looking for coolant buildup in it next morning instead of jumping to conclusions.

-- yeah, its common for valves to be slightly wet with oil on older engine/head. If it gets bad enough, it will cause DPF clogging (or smoking issues for trucks that have been de-mandated).