VW Taos Engine Light + Sluggish Performance Fix Tips

Recently had similar symptoms with a 2019 VW Tiguan. The flashing check engine light combined with poor performance pointed to a failing heat sensor in the exhaust system. The sensor was giving incorrect readings to the emission control unit, causing the engine to run rich. After inspection, the mechanic found a small exhaust leak near the catalytic converter, which was affecting the sensor readings. The exhaust component needed replacement along with the faulty sensor. This was a serious issue that required immediate attention, as running rich can damage the catalytic converter and other engine components. The repair involved: Full diagnostic scan, Smoke test to locate the exhaust leak, Sensor replacement, Exhaust system repair, System recalibration Recommend getting it checked soon, as these symptoms typically worsen and can lead to more expensive repairs if left unaddressed. The diagnostic process is straightforward when done with proper equipment, and most shops can identify the exact issue within an hour of testing. Would suggest requesting a smoke test specifically, as it will quickly reveal any exhaust leaks that might be causing the sensor issues.

Thanks for sharing this. I had nearly identical temperature sensor issues with my 2022 Taos last winter. The temperature fluctuation readings were causing similar problems with sluggish performance and poor fuel economy. Glad to hear your mechanic found the root cause with the exhaust leak. Did you remember approximately what the total repair cost was? My repair bill was quite steep at 780€ for the full service. Also curious if youve experienced any related issues since the fix? My car has been running perfectly after the exhaust sensor replacement, but always good to know what to watch out for.

Just got the paperwork from my repair, the total came to 265€ for fixing both the exhaust system leak and replacing the faulty exhaust temperature sensor. Much more reasonable than your bill. The smoke test quickly revealed the exact location of the leak, which helped keep diagnostic time and costs down. The car has been running flawlessly for the past 6 months since the repair. No more temperature fluctuation issues, fuel economy is back to normal, and the engine light has stayed off. The emission control system is working perfectly now that the sensor is providing accurate readings. One tip: keeping records of any temperature sensor or exhaust system repairs helps track if similar issues develop in the future. So far, I havent needed to use mine, but its good practice for maintaining the vehicle.

Thanks everyone for the helpful information. I finally got my car checked out at a local shop that specializes in VW diagnostics. The mechanic found that the heat sensor was completely shot, causing erratic temperature fluctuation readings. The engine management system was getting confused by these false signals. The repair was straightforward, they replaced the faulty sensor and did a full system recalibration. Total cost came to 425€, which seems fair given the diagnostic work involved. The emission control system is now working perfectly, fuel economy is back to normal, and the engine feels responsive again. The mechanic showed me the old sensor, it was covered in carbon deposits which explained the incorrect readings. They recommended checking the exhaust components annually to catch any developing issues early. Really glad I got this fixed before it could cause more serious problems.