I inadvertently posted this in wrong section. Belongs here:

Took my 2012 Duramax K3500 DRW in last week for the 3rd time to address regens that occur every 200 miles. last time, they replaced the DEF injector but no improvement. This time
they discussed with GM Tech and ultimately concluded EGR valve was staying open, and replaced it. Just got it back last Friday so cannot tell you whether this was succesfful yet. My question is"can anyone tell me how the EGR valve would affect regens of the DPF"? Does it make sense?