If I'm understanding you correctly, you've installed an aftermarket performance chip into the vehicle which has taken the car from 140 PS to 170 PS.
(NOTE: For those who don't know, a "PS" is a power unit known as pferdestarke. 1 PS = 0.98632007 HP ... Yah, I had to look it up as well.)
If my assessment of what you've done to your vehicle is correct, then yes, the chip could be causing the issue with the DPF. In diesel engines, the easiest way to produce more power is through one of two means (or both):
- Allow the engine to rev higher
- Introduce more fuel into the combustion chamber
The first of these will most likely not affect the DPF, however, introducing more fuel certainly can. Most diesel engines run in a lean burn state, which means there's more oxygen in the combustion than the engine can use. Diesel engines can run perfectly well here (unlike gasoline engines). When you ad more fuel during any given combustion event, you utilize more of that free oxygen, and thus create more power. The thing is, in the process you also create more particulate matter which the DPF must then clean up, which means it will clog faster. Filter regeneration will clean it up for a period of time, but ultimately it will clog back up.
Bottom line here is, I'd suggest you are in the neighborhood when you are wondering if the chip is causing you this issue. I'd think it most definitely is causing it.