In an investigation carried out by the BBC’s ‘Inside Out’ TV show, it has been found that some garages are illegally removing a vehicle’s Diesel Particulate Filter (DPF) instead of replacing it when faulty. Five out of ten garages that were investigated in Staffordshire offered to remove the DPF rather than replace it in a job that could save the customer thousands of pounds. The DPF filters out a lot of the harmful emissions that get pumped out by exhausts, so if removed, the harmful effect on air quality and the atmosphere can be drastic (see earlier hub story here). If a diesel vehicle does not have a DPF it should be an automatic MOT fail, however some garages investigated offered to replace it with an empty container that looks like a DPF, just to pass the testing.
You can find more details here at the bbc.co.uk