Mercedes-Benz ML350 check engine light issue after EGR system replacement and NOX sensor upgrade on Mercedes-Benz ML350

Some Mercedes-Benz ML350 owners report experiencing persistent check engine light issues even after replacing the EGR system and upgrading the NOx sensor. Despite these upgrades, the check engine light may continue to illuminate, suggesting unresolved underlying problems. Owners also note the importance of ensuring that all EGR system components, such as the EGR valve, transducer, and temperature sensor, are functioning correctly to avoid triggering the light. Additionally, if the newly upgraded NOx sensor malfunctions or is improperly calibrated, it can also lead to the check engine light activation. To tackle this issue, some owners recommend performing thorough diagnostics using an OBD-II scanner to retrieve error codes and identify any lingering issues within the EGR system or NOx sensor. If these troubleshooting efforts do not resolve the problem, seeking assistance from a qualified Mercedes-Benz mechanic or dealership is advisable for proper diagnosis and repair of complex engine issues.