Audi P200200 Bodged Remap DPF Delete

Audi P0299 Underboost Caused by a Bodged DPF Remap on a P200200 fault on an Audi Q5 A warning light and P0299 turbo underboost would usually send you looking for boost leaks, split hoses or turbo trouble. On this Audi Q5, the real fault sat further down the exhaust. A previous software change had switched off DPF regeneration, but the DPF itself was still fitted, so it slowly blocked up and dragged the car into limp mode. The result was a strange mix of symptoms that only made sense once the live data was checked properly. Why this Audi Q5 kept going into limp mode When the Q5 first came in, it would drop into limp mode on the road and log P0299. Differential pressure had been as high as 75 mbar. After an initial DPF clean, it dropped to 6 mbar, then later sat around 26 mbar when the car returned for the permanent fix. The main symptoms were clear: * Engine light and limp mode on a road test * High DPF pressure, despite no obvious boost leak * No useful soot loading data, even when engine speed changed The live data gave the game away The pressure reading moved, but the soot figure stayed stuck at 0.1 g. That mismatch pointed to one thing, the DPF had been deleted in software, but not removed physically. In other words, the filter was still there, still catching soot, but it could no longer regenerate. The real cause behind the bad remap The owner had only bought the car two weeks earlier. After several visits elsewhere, nobody had pinned it down. The seller later admitted the car had previously had a DPF "software fix". That appears to have been an attempt to deal with a P2002 fault. On these cars, that can be tied to an EGR cooler issue rather than a failed DPF. Instead of fixing the root cause properly, someone altered the software badly enough to stop regeneration. If the DPF is disabled in software but left in place, it still blocks up. It just loses the only system that can clear it. The data backed that up. The car showed roughly 5,000 km since its last regen, which should never happen on a working system. How the ECU was put back right The repair started with battery support, an Autotuner tool and a full ECU read. The file already on the car was saved, then sent off so the ECU could be reflashed correctly. Rather than deleting the DPF again, the replacement software restored regeneration and addressed the false P2002 issue. The workshop had already spent two years testing software for these vehicles, working with the OBD Company and Remapping Company in Chesterfield to get a proper fix. Test drive proves the DPF works again Once flashed, the Audi showed no DTCs at rest. Better still, exhaust gas temperature readings returned, and the soot value jumped to 24 g, which meant the ECU was now reading the DPF properly. A 10 to 20 mile test drive confirmed the rest. The car started an active regen at around 650°C, soot loading dropped, and the distance since last regen reset to 0.9 km. Back at the workshop, pressure settled to 26 mbar under 200°C, then 5 mbar at idle, with 5.83 g of soot. The exhaust tip was clean too, another sign the DPF was doing its job. In the end, this Audi Q5 didn't need a delete at all. It needed proper diagnosis, a clean DPF, an EGR cooler clean and software that still allowed regeneration. That fixed the underboost fault, brought the power back and left the car working as it should. scan tool link... 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 my Kingbolen Affiliate Link... https://kingbolentool.com/products/kingbolen-k6-pro-all-systems-bidirectional-test-obd2-tpms-diagnostic-scanner-with-2-years-free-update?ref=iq39r3l2