I've fixed the problem actually twice, first time (when the connector issue was brought up) several years ago. I did not had a problem with the connector myself, but the sensor is differential analog sensor; if I remember correctly 0 Pa means half Vcc (operating voltage) on the output. Broken connection would mean constant or intermittent full or zero value. I do not remember anymore how I came to the conclusion it is the sensor, but I changed it and it fixed the problem.
The second one was recently - occasionally "engine fault" light comes on and in the failure codes you could see the DPF sensor values were not plausible. In idle the reading was negative (should never be) and with the sensor test it was clear it is not OK. I purchased a new one and installed it and the problem went away.
If you end up changing the sensor, check the connector as well (a clean up would do no harm) as well as the tubes to DPF. I used compressed air to blow any carbon off inside the tubes.
If you plan to keep the car longer, my recommendation would be to buy a Openport (or a clone if you want to control the budget) and find the SW you need from here,