Insignia DPF Pressure Sensor Fault

Sounds frustrating. I had a similar thing with my old Renault Megane. Warning lights and power loss are never good. The low exhaust pressure thing is interesting, though. Have you checked the pressure sensor itself? Mine was faulty, and it caused all sorts of weird issues. Could be worth a look before you start thinking about the DPF being completely clogged.

My knowledge of vehicle mechanics is limited. Could you elaborate on the location of this pressure sensor and how to ascertain if it's defective? Are there specific diagnostic tests to conduct before seeking professional help?

Honestly, finding it can be a pain, even with a manual. It's usually somewhere near the DPF itself in the exhaust system, connected with some little hoses. Diagnosing it properly usually needs some decent diagnostic gear to read the pressure properly. If you're not confident, I'd say bite the bullet and take it to a workshop. At least they can tell you for sure what's up. Could save you time and money in the long run!

Based on your recommendation, and considering my limited mechanical expertise, I sought professional assistance at a local reputable workshop. Following a thorough inspection, it was determined that the exhaust back pressure sensor was defective, precisely as you had suggested. The issue has since been rectified with a replacement sensor, incurring a total repair cost of 245€.