
A DPF reading 400 per cent full: Mercedes A200 diesel
A Stourbridge customer brought this one in with a simple complaint: no power. The diagnostics gave a less simple answer. The diesel particulate filter was reading 400 per cent full, which is the figure on the scanner in the photo, and that is not a number everyday driving produces.
A DPF traps soot from the exhaust and burns it off periodically. This one had blocked solid because a component had failed rather than because of how the car was being driven: the exhaust temperature sensor that should have been managing that burn-off was dead. With the filter off the car, it was completely blocked.
Rather than a new filter, the customer chose a secondhand unit that we had professionally cleaned, which saved a good deal of money. That went on along with a new lambda sensor and a new exhaust temperature sensor, then every fault code was cleared and the system values reset to zero. To be clear about what that means: the filter was replaced, not deleted. Removing a DPF is illegal and an automatic MOT failure, and we do not do it.
Then a road test. Elliot's word for the difference against how it arrived was unbelievable. Running perfectly.

