Below is some important information with regards to fitting a DPF on a Vauxhall Zafira.
Diagnostic Checks & Installation
Before fitting the DPF diagnostic checks should be carried out with an appropriate fault code reader to establish any codes held within the ECU. Comprehensive testing of the components listed below should also be carried out as a fault with one of them either alone or in combination could lead to DPF failure. Be aware that an unresolved fault with the vehicle that illuminates the engine management light will usually prevent the regeneration process from initiating and therefore the DPF will become blocked.
DPF Pressure Pipes & Sensor – checks should be made to ensure all pipes are free from damage or blockages and the differential pressure sensor is working correctly. It is best practice to replace the differential pressure sensor when fitting a new DPF.
Sensor Checks – check that the exhaust gas temperature is operating correctly. If it not registering the temperature within the DPF correctly it will prevent the regeneration process from initiating and therefore the DPF will become blocked.
EGR System – check the Exhaust Gas Re-circulation valve is working correctly and is not blocked. As a minimum the EGR valve must be removed and cleaned before replacing the DPF. A faulty EGR valve is the single most common cause of blocking the DPF on a Zafira. It is best practice to replace the EGR valve when fitting a new DPF.
Swirl Flaps - check the swirl flaps are operating correctly (if your car has them) as the rod can fall off due to wear and this will cause the DPF to become blocked.
DPF Installation & Set Up
Once the fault that caused the previous DPF to fail has been rectified the new DPF can be fitted. The new DPF should be fitted loosely to line it up correctly with the rest of the exhaust system before tightening it up. An appropriate diagnostic tool will be required to reset the ECU in accordance with the manufacturer’s guideline. This will include telling the car that a new DPF has been fitted, resetting the ash counter and calibrating the differential pressure sensor. Failure to complete the set up process correctly can cause the new DPF to become blocked as the vehicle is unaware that a replacement unit has been fitted. A forced regeneration may also be part of the reset procedure and if all the correct guidelines have been followed a new aftermarket DPF will work in the same way as the O.E. specification unit did prior to failure.
***A new DPF must be fitted by a competent mechanic/garage that has the required level of diagnostic equipment necessary to complete the set up procedure after installation - failure to adhere to this requirement may invalidate the warranty***
If the procedures set out in this guide have not been followed the new DPF could block up within a very short space of time and may not be able to be regenerated.
We know from our experience (we own and operate a large service/repair centre in North West London (www.jemservice.co.uk) that specialises in DPF problems) that unless you are very comprehensive with your diagnosis and component replacement when fitting the new DPF it can quickly end up the same as the one it is replacing.
The part you have purchased is our best-selling Vauxhall DPF and the most common unit we fit in our workshop. If there is a fault with the vehicle or any of the associated components that has not been rectified (or fails at a later date) that prevents the active regeneration process from initiating or completing the new DPF will become blocked. We have known an incorrectly diagnosed Zafira to block a new DPF within 50 miles but under 300 is most common.
When we replace these units in our workshop we always replace the EGR valve, exhaust gas temperature sensor and differential pressure sensor at the same time and as far as we are aware most Vauxhall dealers adopt the same policy.