Passive Regeneration from golzol's blog

A blockage can occur if your DPF isn’t cleaned properly and regularly, or if regeneration isn’t occurring often or efficiently enough. This can happen, for example, if a vehicle is only used for short journeys, not allowing the temperature of the exhaust to increase enough to burn off the soot in the filter by passive regeneration - DPF Cleaning Process. For more information, please visit our site http://dpffilter.com/