ABSTRACT The emissions legislation in the US and Europe introduce the need for the application of diesel particulate filters (DPF) in most Diesel vehicles. In order to fulfill future OBD legislations, ...

Multiple layers combine to form a functional pressure and movement sensor. "We performed a rigorous set of tests on our sensors with the help of 18 test subjects," said Lee.

So if the DPF reading is say 90% and a regen doesn't take the % down a significant amount then the DPF is beyond fixing. Though I have heard good things about "Wurth" DPF cleaner, Which actually gets ...