G Klasse NOx Sensor and Exhaust Leak

A NOx sensor failure and exhaust leak on a G Klasse is tricky. The cable/plug connection could be it, but be careful before you decide. With the age and mileage, is the exhaust system okay? Corrosion could look like sensor failure. Did you check the sensor's wiring for damage besides the connection?

The exhaust looks good, no rust or damage near the sensor. The wiring looks fine too. Could a bad emission sensor cause both the NOx sensor error and the exhaust leak? Maybe the leak is small and hard to find without special tools?

A bad emission sensor affecting NOx readings is possible, but the exhaust leak is odd. If the visual check and wiring are good, the sensor is likely bad. But, to be sure, take it to a shop with smoke testing gear. They can find the leak and check the sensor under load. It might save money later.

Got it. I'll take the G Klasse for a smoke test and NOx sensor check. Turns out the cable was bad. It's running well now.