Is a remap safe for my engine?
The honest answer depends on the engine in front of you, not on remapping in general. Here is what actually determines it.
Diesel
Why your DPF keeps blocking, and why deleting it is not the answer
It is an MOT failure and it is illegal on a road car. It is also, almost always, a symptom of something cheaper and more useful to fix.
What the filter is doing
A diesel particulate filter catches soot. Periodically the car raises exhaust temperature and burns that soot off — a regeneration — which needs sustained load for ten or fifteen minutes.
A car that never gets that never completes a regeneration. Soot accumulates, back pressure rises, the light comes on, and eventually the car limits itself.
Why yours specifically is blocking
Short journeys are the usual answer, and no amount of software fixes a three-mile commute. But it is not the only one, and assuming it is means people delete filters that were never the problem.
A failing EGR valve, a tired turbo, a leaking injector or a faulty differential pressure sensor all produce the same symptom. So does a car stuck in a regeneration loop because somebody cleared the codes without letting it finish.
The light tells you the filter is full. It does not tell you why, and that difference is the whole job.
Why deleting it is the wrong answer
It is an MOT failure: visual inspection covers it and the test explicitly checks for removal. It is unlawful to use a vehicle on a road with emissions equipment removed. Insurance is a further problem, and resale is a third.
And it does not address the fault. A car deleting its filter because of a leaking injector still has a leaking injector.
What actually works
Diagnose first. Read the soot load, the differential pressure and the regeneration history, and you usually know within the hour whether this is a driving-pattern problem or a component failure.
If it is driving pattern, the answer is a longer run once a fortnight, and sometimes a forced regeneration to reset the count. If it is a component, replace the component. Neither is expensive next to a new filter.
Where tuning fits
A properly written file can help at the margins — a cleaner burn produces less soot to begin with. It is an improvement, not a cure, and we will not sell it as one.
If your journeys are genuinely too short, the honest advice is that a diesel is the wrong car for your life. We have said that to people and meant it.
If you want it checked rather than argued about: send the registration. We will tell you what your engine makes now, and whether there is anything about your car that changes the answer.
Keep reading
Related
How to read a dyno graph without being fooled
Two lines on a chart, and four ways the trade makes them say something they should not.
Remapping, warranty and insurance: the straight version
What a manufacturer can actually decline, what you must tell your insurer, and what it usually costs.
Ready when you are
Find out what yours makes.
Send the registration and we come back with the figures for your exact engine, a fixed price, and anything we would want to check first.
0115 496 0177