Touareg Exhaust Sensor Failure Draining Power & Fuel

Had a similar issue on my 2010 VW Tiguan with the gasoline engine. The check engine light and power loss turned out to be a faulty oxygen sensor in the exhaust system. The symptoms matched exactly, increased fuel consumption, sluggish acceleration, and engine management light. The exhaust sensor replacement was necessary since it affects the engines air-fuel mixture. When these sensors fail, the engine runs rich, leading to poor performance and higher emissions. Temperature fluctuation readings were completely off, causing the engine management system to compensate incorrectly. The repair involved more than just changing the sensor. During inspection, they found corrosion around the sensor housing in the exhaust system, which required additional work to ensure proper sensor function. This was actually a blessing in disguise, as leaving it unchecked could have led to complete exhaust system failure. Worth getting it checked soon, as driving with a malfunctioning sensor can damage the catalytic converter, a much more expensive repair. The emission control system relies heavily on accurate sensor readings to function properly. A professional diagnostic scan can pinpoint exactly which sensor is failing.

Thanks for sharing your experience. Your case sounds very similar to mine. After reading this, I took my Touareg to a shop last week and they confirmed it was indeed the exhaust sensor causing the issues. They also noticed some wear on nearby exhaust components that needed attention. Did you remember roughly how much you paid for the full repair including the extra work on the corroded parts? Also curious if youve had any related issues pop up since the fix? My heat sensor readings are still occasionally showing some unusual values, though everything else seems fine now.

Thanks for the update on your Touareg. The exhaust temperature sensor replacement on my Tiguan was completely successful, and I havent experienced any similar issues since. The total repair cost came to 265€, which included fixing a small leak they discovered in the exhaust system while replacing the sensor. If youre still seeing unusual temperature sensor readings, I would recommend getting that checked again. My engine management system readings normalized completely after the repair. These temperature sensors are crucial for proper exhaust system function, and inconsistent readings could indicate either a calibration issue or another failing sensor. The investment in proper sensor replacement and exhaust component repair was definitely worth it, my fuel consumption returned to normal and the engine performance improved significantly. Make sure they check all related sensors while theyre at it, as sometimes multiple temperature sensors can fail within a short time of each other.

Thanks everyone for the helpful replies. I wanted to share how my repair experience turned out. Got the work done at a local VW specialist after the previous replies helped me understand what to look for. The final repair bill came to 340€, which covered replacing the faulty exhaust sensor and fixing some corroded connections around the temperature sensor housing. The mechanic walked me through the diagnostic process and showed me where the exhaust system had developed issues. The engine management system is now working perfectly, no more check engine light or power loss issues. Fuel economy has returned to normal, and the temperature fluctuation readings have stabilized. The shop also did a complete sensor diagnostic check to ensure no other sensors were showing signs of wear. Much better experience than my previous mechanic visits. The car runs like new again, and I learned a lot about how these exhaust sensors impact overall engine performance. Really glad I got it sorted before any damage occurred to the catalytic converter.