This client purchased a new 2022 Mercedes-Benz C300W. The vehicle was taken to Fletcher Jones Motorcars for servicing multiple times, experiencing a series of mechanical issues shortly after purchase. The issues primarily concerned the vehicle’s check engine light, which would intermittently illuminate, signaling various problems with the car’s engine and emissions systems.
The first service visit occurred a couple years after the initial purchase- when the check engine light came on, and the vehicle showed a P0420 fault code indicating a catalytic converter efficiency issue. During diagnostics, it was found that the downstream oxygen sensor was faulty and causing the error. Technicians performed several tests, including scope tests on the oxygen sensors and a borescope inspection inside the catalytic converter.
They found that the catalyst material and the honeycomb structure appeared intact, with no visible damage. Despite this, the downstream oxygen sensor was replaced due to an intermittent electrical fault, and the issue was resolved at that time. After the repair, the vehicle underwent a road test, and no further codes were detected.
About a month later, the check engine light illuminated again, with a new issue reported in the ME control unit. Diagnostics showed implausible data values within the system, such as missing sensor values related to signal temperature, soot content, and regeneration rate. Upon investigation, the ME control unit was found to have internal faults that led to the data inconsistencies.
The control unit was replaced, and after completing a teach-in of fuel injectors and updating the software, the vehicle’s emissions system began to operate correctly again. A follow-up road test confirmed that the vehicle’s engine was functioning properly, and all the previously missing values were now displaying correctly.
Despite these repairs, the check engine light reappeared a few days later. The same P0420 fault code was found, indicating an issue with the catalytic converter. After additional diagnostics, including a borescope inspection of the catalytic converter, it was determined that the converter was faulty.
The catalytic converter was replaced with a new one, along with the associated exhaust components. Following this repair, the vehicle underwent another road test, and no further issues were found. The check engine light remained off, and all the emission monitors were set.
Overall, the 2022 Mercedes-Benz C300W experienced multiple issues related to its emissions system and electrical components within the first two years of ownership. Our client’s experience highlights concerns involving the catalytic converter, oxygen sensors, and the ME control unit.
Despite multiple repairs, the recurring nature of these issues may indicate deeper, unresolved defects in the vehicle, potentially making it subject to Lemon Law claims for defective vehicles.
After dealing with extensive repairs, this client contacted the Lemon Law Experts for help. With our expertise, a successful buyback was negotiated with Mercedes-Benz, resulting in a statutory refund for the defective 2022 C300W, as well as the payment of the consumer’s legal fees and costs.
Since 2009, the Lemon Law Experts have successfully assisted countless clients with defective vehicle claims, ensuring they receive fair compensation. If you’re facing ongoing issues with your vehicle, contact us today for a free consultation to explore your legal options and determine if a buyback is right for you.
