When one or multiple sensors detect a faulty reading, they will report to the car’s computer, if the right conditions are not being met you will be presented with the aforementioned DPF warning symbol. Luckily having the symbol illuminate is a sure-fire way to tell if you are having DPF issues as the car has already figured out the issue for If MOT testers are letting cars pass with the DPF removed then they probably letting other defects through for a backhander. Any MOT tester caught doing this should not be allowed to test cars again, a 2 year ban is not enough. This article also highlights the fact that a DPF will fail if a diesel car is only driven on short journeys. List of cars which don't have DPF's fitted - bazza. 1.9 PD VAG units, the lower power ones continued into 2008/2009 and do't have them fitted. (They're a Euro 4 design) Not sure what else, some Kias i think and possibly the 1.3 Multijet went on for a while without one. Basically anything Euro 5 has one fitted. Today's diesel cars spit out a lot less pollution than older models. A combination of a diesel particulate filter (DPF) and NOx-reducing additives, such as AdBlue, mean you can drive a Euro 6-compliant diesel car with confidence that there'll be no clouds of black smoke pouring out of your tailpipe and that passers-by won't be left choking in your wake. I agree you should go to dealer. So far, I 've had no problem with DPF (15,000 Km). Anyway, according to the supplementary leaflet for "Forester Boxer diesel" I was given by dealer in summer, there are some driving conditions that make DPF's life difficult (too much soot): running all the time at 15 Km/h (9 mph/h) or less, pulling away immediately (no idle first), driving only for short re: BS6 diesel car owners: Have you faced DPF-related issues? DPF issues occur due to various reasons such as idling for long, short and frequent drives etc. Doing a poll on the possible reasons leading to it would have helped to understand more about DPF systems and their suitability for future diesel buyers. Recheck the voltage of the signal. A number between the hoses' pressure readings should appear on the voltage display. For instance, if the front hose reads 1 PSI and the back hose reads 1⁄2 PSI, the signal wire voltage should fall somewhere in the middle, around.8 volts. The DPF differential pressure sensor needs to be changed if there is a There's no 'guarantee' you'll have problems with the DPF, you may go for years without any problems at all. We've had cars with no problems (BMW/Jaguar/Renault) We've had one car with huge DPF problems (Audi A3) But Audi are well known for DPF problems (google search will show you) But even if you do get problems, usually signified by an zD4u.