Vauxhall Vectra 1.9 CDTI DPF Problems
If you are having an issue with your diesel particulate filter (DPF) you are not alone, thousands of people all over the UK that are facing hefty dealer bills to replace DPF’s that cannot be regenerated.
The cost of DPF replacements is very high, with some customers reporting replacement costs of upto £2000 or more…
MPG Tuning used to offer a viable alternative of DPF system removal or replacement at less than 50% of main dealer prices in most cases, unfortunately the government made it illegal to remove your DPF in Feb 2014
However if the DPF in your car is missing and you are getting a warning light and or kicking out clouds of black smoke, we can help you by coding your ecu, not to carry out automatic regeneration until you are able to get the DPF filter replaced.
Obviously complete removal offers a final solution, whereas replacement DPF comes with a 12 months manufacturer warranty.
More Information On DPF’s
A diesel particulate filter sometimes referred to as a DPF removes the diesel particulate matter (or soot) from the exhaust gas of a diesel vehicle, therefore reducing particulate emissions.
Why Do Cars Have DPF’s?
With changes to the car emissions legislation, the ‘Euro 5’ standards will make diesel particulate filters a commonplace in diesel car exhausts as catalytic converters are in petrol cars.
How Does a Diesel Particulate Work or DPF Work?
Unlike a Catalytic Converter a DPF is not a flow through device, and works by forcing the gasses to flow through the filter. As the channels of the filter are blocked at alternate ends, the gasses are forced to flow through the cell walls in order to exit the filter. As the cell walls are porous, the gasses are allowed to pass through, but the particulate matter is deposited on the cell walls. This ensures that only the clean exhaust gasses can exit, and the particulate matter is trapped in the filter.
Passive regeneration takes place automatically on motorway-type runs when the exhaust temperature is high. Many cars don’t get this sort of use though so manufacturers have to design-in ‘active’ regeneration where the engine management computer (ECU) takes control of the process.
Active Regeneration occurs when the level of soot in the filter reaches around 45%. The ECU makes small adjustments to the fuel injection timing and increases the exhaust gas temperature. This increases the exhaust temperature which then initiates the regeneration process, burning away the soot trapped in the DPF.
What Does a Diesel Particulate Filter Do?
The latest diesel engines have a diesel particulate filter (DPF) and a reactivating unit. The DPF collects particulates such as black smoke, soot, HC, etc, which are found in the exhaust gas. The recovery unit is further upstream than the DPF in order to maintain the function of the DPF.
The recovery unit has an oxidation catalyst. The NO and O2 in exhaust gas react with each other, and NO2 is generated. The generated NO2 reacts with the particulates. As a result, the particulates collected in the filter are eliminated, and the DPF is recovered.
The particulates react with O2 at a temperature of approx 550° C. or more, and react with NO2 at a temperature of approx 250° C. or more.
When a vehicle is driven at a low continuous revs on a regular basis, the temperature of exhaust gas is maintained at approx 250° C.
Even given this type of use, provided that NO2 is supplied by the recovering unit, the DPF can achieve continuous recovering state in which particulates are burnt while collecting the particulates.
However, if light load operation continues, the temperature of the exhaust gas falls. As a result, it is difficult to maintain the temperature of the oxidation catalyst further up system than the DPF, so there are situations in which recovery of the DPF is insufficient.
If the continuous recovering function deteriorates, the DPF is in an over-collected state, and clogging by particulates occurs. As a direct result, an exhaust gas pressure increases, and the fuel efficiency and the power performance of the engine will deteriorate.