Wynn's29079 DPF & GPF On-Car Cleaner 500ml

My Audi A4 3.0 TDI (crtc engine code) was in limp mode with blocked DPF caused by faulty EGR valve, now replaced - so had 'drive fault' warnings on start up, cruise control inoperative, no performance. I have the vag-com / vcds cable and software so could see two fault codes, 5188 - particle filter excessive soot - and 5189 - particulate filter bank 1 efficiency below threshold.I warmed the car to normal temperature, removed one of the sensors in the 'upstream' / turbo end of the DPF after soaking it for a few days, then used the whole can of cleaner, spraying into every part of the filter that I could using the long hose supplied - obviously avoid any fumes / wear a proper filter mask. I followed the instructions to let it soak for 30 mins, then started it, let it idle then run at 2,000 RPM then test drive. Initially, no foam came out of the exhaust, unlike in the You Tube video, and at first it seemed to have had no effect. But on the test drive, still in limp mode, grey/black smoke started to come out of the exhaust, for about 15 minutes.When I got back, I cleared the codes, and the car was back to running properly; no warning lights, no limp mode, if anything it felt better than before. I checked the regeneration data and it had just done a 'passive' regeneration on the drive, which it won't do if the fault codes are showing. I was stunned; I was quoted £264 for an on-car clean, this seems to have fixed it for less than £25. Fabulous.

A lot cheaper than paying to have the dpf removed and cleaned. My dpf was blocked badly i put this in left it for 5 minutes then went for a 20 min drive it didn't work until I took the car out the next day for a longer drive then a big cloud of smoke came out and the car had full power again I have my own fault code reader and reset the engine light myself now the car is running perfectly again

Followed instructions, Did nothing, had some smoke when holding revs. That's about it. Still blocked, still have flashing glow plug light. Cleared faults, dpf faults came back, calculated soot mass after using 56.12g, soot mass before using 35.89g, so product only helps to block dpf more

Bear with me as this may be slightly technical. Car is a Seat Leon MK3 2.0 FR, 137k miles. Car is mainly driving round town, school runs and food shops, occasionally runs on the motorway, which is not great for a diesel. Oil ash reading is showing around 50grams (60-70% full). DPF pressure showing around 20-30mbar at idle, and under load it’s showing between 80-220mbar, which is fairly high because of the ash load (blockage). Now, I’ve already used x2 other branded dpf cleaners from GSF car parts before, within the last month. I bought this particular wynns brand as the description shows it would clear soot and ash. My biggest issue (safety) with this product was that the description shows the car needs to be up to temperature, then you send the cleaner in. Now, as I did this after the car was at running temp, the cleaner spray started steaming and soot spitting out of the exhaust gas temp sender straight into my face on the first blast. !!!Wear eye protection!!!! I watched the exhaust temps and they were on 200c. So, I would recommend you wait until temps are under 150 unless your happy with steamy soot flying everywhere. Back to the performance of this. It definitely clears soot, but I wouldn’t say it clears ash very well. My Pressure sensor was showing between 25-30 pre clean, showing same pressure after the clean. Pressure was confirmed with a manual manometer. I guess if your issue is mainly soot, and not ash, then these on car cleaners should work as intended, but if the issue is oil ash, then I suppose it’s best having the DPF taken off and cleaned via reverse flow.

Had an error code on my BMW 520d for the DPF filter, after a quick youtube tutorial decided to give the foam cleaner option a try. This stuff was excellent!! Very straightforward just shake and squirt, leave for 15 mins then go on a 30 minute run. Took the exhaust back pressure from 78 millibar at idle to under 10. Car runs amazing and MPG increased back to 45+mpg from 30 with a blocked DPF. Highly recommended A+++

Done the job perfectly

Was able to empty this into the dpf. Waited 45 minutes to an hour, then started the engine, rev about 2000rpm. All the engine complaints, including dpf, stability errors, disappeared. A week later, I do see occasional white smoke from the exhaust for no reason. It stops soon though. I believe some of the materials still remaining in the dpf. I will keep observing. So far, two weeks down, no more errors and engine struggling.

Soot - carbon builds up in dpf naturally. It should burn 🔥 out itself, too. If anything isn't right, that's not your dpf is bad - it's your engine or very short distance driving, so dpf can't regenerate. This detergent will help for a week or 2, and your problem will come back.Dpf, when regenerates creates ash, like every burning process. This ash accumulates in your dpf filter and it can only be washed away by high pressure cleaning machine. It can't be done on car.Don't get cheated!