Yes. It comes from underneath the truck and on the passenger side. It even feels like a thumping sound. It occured when I pressed the throttle to speed up on the off ramp. The last time this occured was just following a mildly cold start after leaving a restaurant and pressing the throttle down for a quick entrance onto the main road. Immediately following, the check engine light illuminated. Since it went away before I could have it checked the following afternoon, I can only assume it was the dreaded
P2262.

Speaking of regeneration, though I have only a 12 minute commute with most of it within 55-70mph, I have yet to have any warning come up on my overhead computer. Might it be that because the DPF is nearing regeneration and with the acceleration of air into the DPF it was causing a back pressure? If so, why would not the computer tell me that it was about time for the regeneration to take place because the DPF was "80% Full"? It's also only occured during relatively cold conditions. It hasn't ever occured during the afternoon when I return home and accelerate onto the interstate.