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The Engine Tuning Performance Specialists

Audi A4 170 TDI Diesel Particulate Filter Problems & Solutions

Diesel Particulate Filter (DPF) ServicesDPFLIGHT

This page is dedicated to DPF related problems that arise on the Audi A4.
Angel Tuning will try and remove the ‘myth’ around the Diesel Particulate Filter (DPF

Blocked DPF – (Diesel Particulate Filter)

The DPF, or Diesel Particulate Filter to give it the full title, is a device that is fitted to most modern diesel cars that acts as a filter to remove the heavy “particulates” from the exhaust gasses.dpf

It is this unit that gives consumers the impression that the new modern diesel engines are not as smoky as the old ones were. In the main this is true, but partly the reason for the reduced visibility of engine smoke.

For environmental reasons the DPF unit collects all the particulates in the exhaust system while you are driving around town.

This build up then needs to be able to clean itself and “eject” that built up soot

Why is my DPF warning light on?

Well, there could be two reasons for this on an Audi. The easy one to fix is to replace a sensor that calculates the air flow through the filter. If faulty this will send an incorrect message to the ecu instructing it light up your dash and place the vehicle in limp mode.

This could be relatively cheap and easy fix – around £100.
This fault can be quite common on the 170 bhp engine.

Alternatively there is a very high chance the DPF unit itself is blocked, and is unable to clean itself. The unit will either need replacing or removed.

Replacing it will cost around £2000. Removing it will cost around £550 (£650 for a quattro system)

Driving style and type of journey is usually the cause of DPF problems. The unit can only clean itself (or enter a regeneration cycle) once you maintain a constant speed over a period in time WHILE you are in top gear. In other words – on the motorway. If you do not ever let your car have a good run like this then the DPF unit will just continue to fill up until its full. Then its too late!

If you do drive plenty of motorway miles… it will still block up in the end… Every time a successful regeneration cycle is completed (see the new cars down the motorway with smoke pouring out the back like its blown its engine) a small amount of ash residue is left behind. After so long that ash itself is what causes the blockage and no cleaning or forced regenerations will cure that one!

What is a Permanent fix?

Removal is really the only permanent fix. If it has been your driving or journey style that has cause this one to clog up, then it will do the same for the next one unless this style is changed.

Removing the combined DPF & CAT will ensure against a blockage again. You will still pass the MOT. There is no emissions test in the UK on a diesel engine. We have removed lots of these units, if there were any problems we would not be doing it!

Once the unit has been removed you will need to have the engine management (ECU) altered to prevent any further attempts to “regenerate”

Angel Tuning offeres two options

DPF Remapping

Two options are available. Both at same price.

We can either remove the regeneration in the software and leave the performance and economy standard or we can maximise the efficiency of the engine to enhance power and economy

A 170 Tdi that has had the full process of DPF removal and engine software enhancement will ultimately deliver some 200+ bhp and in excess of 320 lbft of torque whilst gaining 8-12% fuel economy


Our charge of £649 includes the physical DPF removal, the work on the engine management system, diagnostic health check and final road test. We are also able to offer EGR (exhaust gas recirculation valve) disabling as part of the process should you require.

For this service you would have to come to us at Banbury, Oxfordshire.

Please note, should you have a Quattro version we would need to add £300 to the price due to the additional work required.

Customer Testimonial

I just wanted to say thank you for the work and effort your guys put in on my car. I’m sorry that the Quattro system complicated the whole operation, but the final result is absolutely spot on.

The combination of the removal of so much back pressure from the exhaust system and your ECU re-map have completely transformed my Audi 170ps, especially the immense torque I now get. Not only is the power delivery far smoother and more practically delivered, but it also makes it a safer drive! I was never happy with Audi’s original factory set up and now its like having a new car all over again!
It is very reassuring to take my car to friendly professional company. I thoroughly recommend your services and will certainly be coming back to you again in the future.
Thanks again,


Angel Tuning now offer a vast array of automotive services from our our Banbury headquarters. At this location we can offer full workshop facilities to cater for your needs, be it from a straight forward service, engine tuning or damage repair to complete vehicle restoration and race preparation. Whatever your needs may be, talk to us and we can provide a cost effective solution