Mercedes GLE Faulty Exhaust Temperature Sensor and Leak

A faulty exhaust temperature sensor certainly aligns with the symptoms you're experiencing. The engine management system relies on those temperature readings to optimize engine performance and emissions. When the sensor malfunctions, it can lead to reduced power, increased fuel consumption, and the check engine light illuminating. You mentioned a possible leak in the exhaust system. This is plausible, as a leak can affect the exhaust gas temperature, causing the sensor to report incorrect values. To clarify, is the sensor reading unusually high or low temperatures?

Thanks for the quick response I'm not sure if the temperature reading is high or low, I just got the error code read at an auto parts store What exactly does the exhaust temperature sensor do, and how would a leak in the exhaust system mess with it

The exhaust temperature sensor, sometimes referred to as a heat sensor, monitors the temperature of the exhaust gases. This information is crucial for the engine management system to control fuel injection, ignition timing, and other parameters to ensure optimal combustion and minimize emissions. If there's a leak in the exhaust system, it can introduce outside air into the exhaust stream, altering the temperature and composition of the gases flowing past the sensor. This can cause the sensor to send inaccurate readings to the engine management system, leading to the issues you're experiencing. Given the symptoms and the error code, it would be best to take your GLE to a qualified workshop to properly diagnose and repair the issue. They can pinpoint the exact location of any leaks and replace the faulty sensor.

Thanks so much for the explanation I took it to the workshop, and you were right They found a small leak in the exhaust manifold near the sensor. They replaced the exhaust temperature sensor and fixed the leak. Total cost was 265€ The car is running great again