VW TDI DPF Issues: Black Smoke & Failed Regeneration

I had a nearly identical issue with my VW Golf TDI from 2002. Having some experience with diesel engines, I recognized similar emission control symptoms right away. The black smoke and failed DPF regeneration cycles were exactly what I experienced. The vehicle emissions warning light was definitely a key indicator, just like in your case. The exhaust back pressure sensor turned out to be the root cause, which was affecting overall engine performance. I took it to a workshop where they ran a proper diagnostic. The pressure sensor was showing incorrect readings, preventing proper exhaust system function. They replaced the sensor and recalibrated the system. Total cost was 245€ including parts and labor. The repair resolved all symptoms, no more black smoke, warning lights cleared, and DPF regeneration working normally again. To better assist with your specific case, could you share: Current mileage on your Bora, How long the warning light has been active, Any recent repairs or maintenance performed, Whether the engine performance issues occur mainly during cold starts or at operating temperature This information would help determine if your situation matches what I experienced and whether the same fix might work for you.

After reading your experience, it matches my symptoms exactly. My Bora has 145862km on the clock, and the warning light started appearing right after the last service two weeks ago. The exhaust sensor diagnosis makes sense given my symptoms. The black smoke mainly appears when the engine is fully warm, especially during highway acceleration. The failed regeneration cycles are becoming more frequent. Your repair costs seem reasonable for fixing the pressure sensor. Before spending money on parts, I will have the vehicle diagnostics done to confirm this is the root cause. Better to verify the exact issue than replace components unnecessarily. Thanks for sharing the specific repair details and results. Will update once I have professional confirmation on whether my exhaust system needs the same fix.

Thanks for the update on your Bora. Your mileage and symptom pattern strongly suggest the exhaust back pressure sensor is indeed the culprit, especially since the issues started after the service. My Golf showed identical behavior at around 150000km. The timing of your warning light appearing after service is particularly telling. Sometimes these sensors can be disturbed during routine maintenance, especially if any exhaust system work was done. When I had my car diagnosed, the technician mentioned this is a common occurrence. Car maintenance records showed this was a known issue for our engine type around this mileage. The black smoke during warm highway acceleration was exactly what I experienced before the repair. It is a classic sign of the pressure sensor misreading exhaust flow. Getting professional vehicle diagnostics is definitely the right approach. When they tested mine, the diagnostic report clearly showed sensor voltage irregularities. Make sure they specifically check the exhaust sensor readings under load conditions, as this revealed the fault most clearly in my case. Would be interested to hear what the diagnostic results show. The repair should be straightforward if it turns out to be the same sensor issue.

Current exhaust problems with my VW Bora have really been concerning me, but your shared repair experience gives me confidence in finding a solution. Looking at the similarities between our cases, especially the timing after service and identical emission control symptoms, makes me more certain about the diagnosis. The exhaust back pressure sensor definitely seems to be the prime suspect. The fact that your Golf had the same issues around 150000km, close to my current mileage of 145862km, is quite telling. My black smoke during warm highway acceleration matches your experience perfectly. I will proceed with professional diagnostics to verify the sensor issue, focusing on checking voltage readings under load as you suggested. The 245€ repair cost seems reasonable for fixing this car maintenance problem. Having a clear direction for the auto repair helps reduce the stress of dealing with these exhaust system issues. Will make sure to get a complete diagnostic report before proceeding with any parts replacement. Once I confirm the pressure sensor is causing the emission control problems, I can move forward with the repair confidently. Thanks for sharing such detailed insights about your similar experience.