Peugeot Boxer DPF Fault: Why Six Forced Regens Didn't Fix It

Peugeot Boxer DPF Fault: Why Six Forced Regens Didn't Fix It For business enquiries email [email protected] A blocked DPF can turn a camper van into a money pit, especially when one failed fix leads to another. That was the case with this Peugeot Boxer at O'Rileys Autos, which arrived with the engine light on, the skid control light on, and 123,000 miles on the clock. The van had already been through several garages, two DPF cleans, and six forced regenerations. None of it solved the pressure problem, so the next step had to be a proper diagnosis. The history pointed to one problem This Boxer had already had plenty of work thrown at it. The owner said two people had cleaned the DPF, yet the pressure reading stayed high. After that, another garage ran six forced regens in a row, and that still didn't clear the fault. As we put it, using a forced regen to fix a blocked DPF is like putting air into a flat tyre. It might move for a bit, but the fault is still there. With the Kingbolen K8 Pro plugged in, the fault codes showed P2463, P246C and P24A4, plus temporary faults in the deNOx system. Live data made the main issue clear: DPF pressure was about 37 mbar at idle, when it should have been around 6 mbar or less. The system also showed about 120 km since the last regen, and the van had reportedly had a new DPF around the same distance ago. scan tool available at... 5% Off Kingbolen K8 Pro all system scan tool Lifetime free update Discount code YZHKNH36 End 2026-3-16 https://www.amazon.co.uk/dp/B0FL73NZZZ Why the DPF had to come off Because the pressure was far too high, the van went up on ramps for removal and inspection of the DPF. The plan was simple, inspect it first, then decide whether it was blocked with ash or damaged by all those regens. A rusty clamp had to come off, along with the additive injector connection, hoses and mounts. Once removed, Brian checked inside with a camera. The rear of the filter looked clean, and there was no soot coming out, which suggested it had not melted. The front section could not be seen fully because of the internal swirl flaps, but the signs were good enough to continue with cleaning rather than replacement. Backflushing the ash out properly The filter then went onto a Carbon Clean DCS 16 machine in the service van, which also carried a compressor and a 500-litre water tank. The DPF was strapped down, the openings were blocked off, and a roughly 50:1 mix of cleaner and water was flushed through it. available at... DPF Cleaning Machines & Carbon Removal - Carbon Clean UK https://share.google/5ghPbHRC4ElhzuBPC What came out told the story. The waste water was full of red ash, the kind of residue that simple on-car cleaning often leaves behind. Flush after flush, the water got clearer until it stopped changing colour. This quick comparison showed how the numbers StagePressure readingInitial idle reading 37 mbar After refit, still wet about 35 mbar. After drying and revving 56 mbar. Settled idle reading 4 mbar. After reset, idle1 to 2 mbar. After reset, 3,000 rpm 22 to 25 mbar. The reset, the road test checks, and the result Once the DPF was back on, the van still showed high pressure for a short time because the filter was wet. Holding the revs up allowed it to dry, and the live readings began to fall. Faults could then be cleared, and the rev restriction disappeared. we also had to tell the ECU that the particulate filter had been replaced, using the scanner's special functions under Spare part, Emissions, Particulate filter. After that reset, the pressure settled to 1 to 2 mbar at idle and 22 to 25 mbar at 3,000 rpm, well within an acceptable range. The fault lights stayed off, and the van would rev cleanly again. The strongest takeaway from this Boxer is simple: ash loading will not be fixed by repeated forced regens. Once the ash was backflushed out and the system reset correctly, the pressure dropped to where it should have been, and the van was finally sorted.