VW Crafter: Exhaust Sensor Issues Impact Performance

I had a similar situation with my VW Transporter 2.0 TDI from 2010. As someone with moderate experience in car maintenance, I initially thought it might be just a sensor issue, but it turned out to be more complex. The symptoms matched yours exactly, check engine light, reduced power, and higher fuel consumption. After inspection, my workshop found a crack in the exhaust manifold, causing incorrect readings from the exhaust sensor. The leak was affecting the entire emission control system. The repair included: Full diagnostic scan, Visual inspection of exhaust components, Replacement of damaged exhaust parts, New exhaust sensor installation, System recalibration Total cost was 265€ and resolved all issues completely. Engine performance returned to normal, and fuel consumption improved significantly. For a more accurate diagnosis of your Crafter, could you share: Current mileage, Any unusual sounds from the exhaust area, Whether the check engine light is constant or intermittent, If you notice any black smoke, Recent maintenance history This information would help determine if your issue matches what I experienced or might be something different in your exhaust system.

Thanks for sharing your experience. My Crafter just had its service last month, currently at 93571KM. Your description of the symptoms matches exactly what I am experiencing, especially the temperature fluctuation issues. The mechanic performed basic diagnostics but was uncertain whether a simple temperature sensor replacement would solve the problem. Since the exhaust component repair on your vehicle fixed similar symptoms, I will request a thorough inspection of the entire exhaust system, focusing on potential cracks or damage that might affect sensor readings. Did your repair shop mention how they identified the crack in the exhaust manifold? Was it visible during visual inspection or did they need special equipment?

Good point about the diagnostic process. In my case, the crack wasnt immediately visible during the initial inspection. The repair shop used specialized pressure testing equipment to locate the exact point of the exhaust leak, which was hidden behind other engine management components. The testing process took about an hour and revealed a hairline crack that was affecting the temperature sensor readings. This explained why the engine management system was receiving incorrect data and reducing power output as a safety measure. A useful tip from my experience: request a smoke test of the entire exhaust system. This method clearly showed how the exhaust gases were escaping and helped confirm the faulty exhaust component was indeed the root cause, not just a sensor malfunction. The repair time was about 4 hours total, including: Pressure and smoke testing, Manifold replacement, Temperature sensor replacement, System calibration The emission control systems on these engines are quite sensitive to any exhaust leaks. Getting a complete diagnosis saved me from repeatedly replacing parts without solving the underlying issue.

Thank you for that detailed insight into the diagnostic process. The information about pressure and smoke testing is particularly valuable for my situation. It makes sense that these tests would reveal issues that arent obvious during a standard visual inspection. Based on your experience, I have scheduled a comprehensive inspection next week, specifically requesting both pressure and smoke testing of the exhaust system. Your repair timeline of 4 hours helps me plan accordingly. I will make sure they check for hairline cracks that could be affecting the heat sensor readings, rather than just assuming a faulty temperature sensor is the only issue. The fact that your vehicle showed such clear improvement after fixing both the exhaust leak and sensor gives me confidence that a thorough diagnosis will identify the root cause of my Crafters problems. The sensitivity of these emission control systems to exhaust leaks explains why the engine management system might be responding with reduced power. I will update this thread once I have the diagnostic results and repair outcome, as it might help others experiencing similar temperature fluctuation issues with their vehicles.