Mazda don't want to know If you're a CX7 owner you need to watch

 

Most of the people on this site are in the USA, which never got diesels.

I would suspect poor servicing & poor quality engine oil played the biggest part in failure.

The ECU/PCM monitors oil quality/dilution & will alert the driver via the DPF light if there is any issues.

 

My CX7 has a full main dealer service history from the very first day I took delivery (the same one the car was purchaced from) It has wanted for nothing. Whatever it needed it has had including my love and care. It's last service was the 75000 mile service even though it had only done 53000 miles at the time and that was only two months ago.