Answered by: Neil Briscoe - Complete Car Adviser - @neilmbriscoe

Answer

Hi David,

Diesel particulate filter issues are common to all modern diesel engines and it's basically down to how the car is driven. It's part of why diesels aren't suitable for low mileage, short-hop drivers. 

The Mazda issue appears to be down to the fact that the diesel particulate filter warning light double-jobs as a warning light for other exhaust and emissions issues, meaning that fixing or replacing the filter might not be the whole story. Essentially, if you've got this problem, it's best sorted by a trained and informed Mazda mechanic, as they can interrogate the engine's computer in detail.