VW Phaeton Diesel EGR & DPF Warning Light Alert

Had identical symptoms on a 2007 VW Touareg V6 TDI. The main issue was a faulty exhaust back pressure sensor causing incorrect DPF regeneration cycles. The symptoms match exactly, multiple warning lights, reduced engine performance, and dark exhaust smoke. The defective sensor was misreading the particulate filter pressure, preventing proper regeneration cycles from completing. The repair involved: Diagnostic testing to confirm pressure sensor failure, Complete replacement of exhaust back pressure sensor, Forced DPF regeneration cycle, ECU reset to clear fault codes This was a serious repair requiring specialized diagnostic equipment. The faulty sensor caused excessive soot buildup in the particulate filter, which could have led to complete DPF failure if left unaddressed. These symptoms should not be ignored as they indicate the diesel exhaust system is not functioning properly. Continued driving with low pressure readings can damage both the DPF and engine components. Recommend having it diagnosed at a shop with experience in VW diesel exhaust systems and DPF regeneration procedures.

Thanks for sharing your experience with the diesel exhaust system issues. The symptoms you described with your Touareg sound exactly like what I am experiencing with the Phaeton right now. Really helpful to know about the faulty back pressure sensor, makes sense how that would cause DPF issues and affect the regeneration cycles. Just the exhaust symptoms and warning lights alone had me worried about a complete particulate filter replacement. How much did you end up paying for the full repair with sensor replacement and regeneration? Also curious if you have had any recurring low pressure problems or reduced power issues since getting it fixed?

Glad I could help explain the diesel exhaust system issues. My repair experience turned out well, the pressure sensor replacement and DPF regeneration fixed the problems completely. The total repair cost was 245€, which covered the exhaust back pressure sensor, diagnostic work, and forcing a regen cycle. Since fixing the faulty sensor, the low pressure readings and warning lights have not returned. The car runs perfectly with no reduced power or exhaust smoke issues. A properly working pressure sensor is crucial for the DPF regeneration process to function correctly. Looking back, catching the defective sensor early prevented much more expensive damage to the particulate filter. Regular DPF regeneration cycles are now completing as they should, keeping the exhaust system working efficiently. It sounds like your Phaeton has very similar symptoms, so checking the pressure sensor would be a good starting point before assuming worst-case scenarios like full DPF replacement.

Just wanted to update on how things turned out with my Phaeton emission control issues. Took it to a specialized VW diesel shop and the diagnosis confirmed what was suggested, a faulty pressure sensor causing DPF regeneration problems. The repair went smoothly but cost a bit more than expected at 380€. The shop replaced the defective sensor, ran a forced particulate filter regeneration, and cleared all the fault codes. They also cleaned some soot buildup that had accumulated due to the incomplete regeneration cycles. Been driving for about two weeks now and all warning lights have stayed off. No more dark smoke or exhaust smell issues. The engine performance is back to normal with no reduced power warnings. Really relieved it was just the pressure sensor and not a complete DPF replacement job. Thanks again for helping me avoid another expensive misdiagnosis. Having specific information about the exhaust back pressure sensor made a big difference when discussing the repairs with the shop.