A Diesel Particle Filter (DPF) is currently only used in diesel engines. If the manufacturer of the engine isn’t able to drop the amount of emissions/particles below a given threshold without particle filter. A DPF will be equipped to keep the tailpipe emission/particles below the threshold.

Red arrow indicated both Catalyst and DPF on BMW N57D30TOP engine Diesel particle filters (further named as DPF) are there to filter the exhaust gas from particles that can harm the environment and thus human health.

The downside of these filters are

• they are expensive to replace (~ €1500,- )
• regular replacement mileage could be near 200.000km/125.000miles.
• they can restrict power output and damage the turbocharger of the engine once fulfilled with soot or ash
• can cause higher fuel consumption by more than regular regenerations*
• due to regenerations oil can dilute and cause engine/turbocharger failure due to oil dilution.

Most diesel engines inject during the exhaust stroke of the 4 cylinder stroke of an diesel engine (intake,compres, power, exhaust). This extra injection causes extra heat during that event and with special after injection trategies the DPF can be “cleaned” with the higher temperature. Some other manufacturers also use an additive to clean the DPF. Injecting during the exhaust stroke doesn’t bring you more torque or power and therefore it is only used for DPF regeneration(s).

Karreman Engineering is able to remove the filter itself and those strategies and injections that clean the DPF. Also Karreman Engineering is able to remove error codes related to a removed DPF. With our DPF OFF service we can remove the DPF from your car and/or algorithms inside the ECU (Engine Control Unit) that cause regenerations for the DPF.

With the removal of your DPF you have the following benefits

• No more regenerations that cause high temperature to turbocharger and exhaust manifold
• There is less oil dilution caused by regenerations (lower risk of oil dilution)
• The choice of oil is wider, you are no longer restricted to oils with low ash rate for an engine fitted with a DPF. Often oils that are not meant for engines with DPF have a higher amount of sink that protects the engine better and can be used without a DPF
• Less backpressure (if the DPF was clogged or fulfilled) which can provide more power and better spool up of the turbo pressure

Once the DPF is removed from your vehicle it is possible that it doesn’t meet your country emission regulation. Therefore it is forbidden to use a vehicle with DPF OFF functionality on the public roads there were this is not approved.

Karreman Engineering is not responsible for those who use this were not applicable. The user agrees the terms and conditions once the service is payed and the work is executed by our staff.

If you do not wish to delete the DPF from your car but rather have a replacement we can offer you the service to replace the DPF, reprogram the engine control unit that a new DPF is fitted and supply you a new or cleaned DPF.
Besides this we are able to read out a large amount of parameters from the engine control unit to observe the DPF conditions. A list of available parameters (if supported by the cars ECU) can be seen below:

• Ash mass or particle filter load
• Difference pressure over the DPF
• Absolute pressure before the DPF
• Temperature before the catalytic converter
• Temperature before the particle filter or after the catalytic converter
• Mileage and time driven since last DPF regeneration
• Fuel and time used since last regeneration
• - Number of regenerations attempts
• - Number of successful regenerations

When DPFs are clogged before a regular mileage interval an observation must be made to the engine to inspect if other components caused the DPF to fail. For instance, injectors with wrong spray pattern can give a wrong combustion results with high soot level as a result. This might not be observed by the driver but can cause damage to the DPF. We inspect the DPF conditions during regular maintenance (oil service) of your vehicle there were applicable, desired by the customer and capability by our tools. This way we can detect if the soot levels in the ECU are expected to be with the mileage the car has covered.