On December 5th 2013 we were notified of the following changes:
From early February 2014 your vehicles annual MOT test will now include checking for the presence of a diesel particulate filter, this visual check only applies to vehicles that were originally fitted with a DPF at time of manufacture. Some manufacturers started fitting these filters from as early as 2000 (Peugeot & Citroen, BMW 2005) but only since 2009 was it compulsory, due to Euro 5 emissions, for new diesel cars and vans to have them fitted.
From what we are led to believe, the MOT test requires the VOSA approved vehicle tester to initially check to see that where applicable, subject to vehicle model, year and make, a DPF is still present. If the DPF canister is not present and a “straight through” link pipe has been put in its place (like some of our competitors use) the vehicle will fail the test. CRD Performance ALWAYS refits the original canister after cutting the unit open and removing the failed filter material therefore guaranteeing a visual MOT pass. Some repairers, to subsidise repair costs, remove and sell the original DPF’s which allows them to charge below normal prices for removal.
Having read some of the information available and published by The Department of Transport and VOSA it seems the MOT Tester is not allowed to tamper in any way with the DPF canister. Even if he suspects the DPF may have been removed from inside the canister he cannot remove it for inspection or for example drill into it, even if it appears to have been separated and welded back together.
Following a visual pass the vehicle will now have its tailpipe emissions tested for smoke content, this test is carried out using an opacity meter that monitors, using a light beam, how dense the smoke is. Vehicles manufactured before 2009 have to achieve a smoke level not exceeding 3.0m-1 (turbocharged) or 2.5m-1 if naturally aspirated. From sometime in 2009, when probably most vehicles have been manufactured with a DPF, smoke levels no higher than 1.5-m have to be achieved for an MOT pass.
Typically, a vehicle fitted with a functioning or even blocked DPF will achieve a smoke test reading of between 0m-1 to 0.5m-1, even if the vehicle has a running fault that could soon cause a filter to fail.
With the DPF removed and the vehicles electronic control unit (ECU) re-programmed to ignore the missing filter (this is to stop it going into “limp home” mode) there is still a very good chance of it passing its MOT test. This is so long as the engine is properly serviced and any faults relating to exhaust gas recirculation (EGR), MAF Sensor, injectors, boost leaks, intercooler or exhaust air leaks, cam timing, compression, fuel quality, pressure or engine management faults have been correctly diagnosed and rectified.
Equally important is the ECU Re-flash map used, most customers opt for a quality performance and economy map when removing their DPF’s, most of these maps will still pass an MOT providing all else is well and the engine recently serviced.
If a vehicle were to fail its emissions MOT test it is often possible for CRD Performance to either change the ECU map for a cleaner map or to even temporarily reduce the engines fuelling using the in house developed Select-a-map diesel tuning box.
Probably, and most important of all, the customer should be made aware exactly what changes have been made to their vehicles ECU map. Some DPF removal companies often delete any ongoing fault codes from the ECU therefore making it almost impossible for other garages to diagnose future faults. Should the customer decide to maybe replace the DPF and put the vehicle back to standard, or even to sell it on, we can provide them with a CD or E-mail of their original ECU file that can be re-installed by any remapping company.
When shopping around for a repairer to carry out DPF removal customers should be aware that just a branded ECU performance/economy re-map, without DPF or EGR deletion costs between £250.00 and £400.00, the procedure to correctly delete the DPF involves exactly the same time and equipment. The internet is full of back street garages or mobile tuners willing to carry out the full removal procedure for very little cost, these should be avoided.