Well, it was too good to last. After quite a long time without trouble codes being thrown I've got a new one: P 2547 (Diesel Particulate Filter Differential Pressure Sensor Circuit High). It happened first about a week ago, just driving normally. I erased the CEL with my code reader and now it's back again (I'm not clearing code this time to see if CEL extinguishes by itself). Truck is bone stock and still runs well.

Question: what does this code mean (specifically, what does it mean when it reads "circuit high"?).
Is this indicating something serious or is it just a nuisance code?

I'm glad I have 60k miles and about 4 1/2 years left on the emissions warranty but shudder at the thought of having to pay to have future emissions
problems fixed over and over again. I'm beginning to admire you guys who've eliminated these problems by "losing" parts