I am reporting an issue with a 2020 Chevrolet Silverado 1500 equipped with the 3.0L Duramax diesel engine. The vehicle experienced a failure of the NOx Sensor Position 2, which significantly impacted performance and emissions compliance. GM previously issued Emission Recall N212351211 (March 7, 2023) for other diesel Silverado models regarding improper ECM detection of NOx sensor faults. The issue in my vehicle appears functionally identical, yet this engine and model were not included in that recall. The sensor was replaced and reprogrammed at a Chevrolet dealership at the owneras expense. After contacting Chevrolet, a customer retention check was provided, covering roughly half of the total cost. While appreciated, the remaining cost burden remains significant. If this model is eventually included in the recall, it may allow for full reimbursement and support for other affected owners. Online forums show that many 3.0L Duramax owners are experiencing similar failures, suggesting this may be a widespread and systemic defect. Due to the strong similarities with the recalled condition in other models, I respectfully request that NHTSA investigate whether this recall should be expanded to cover additional affected vehicles. This issue presents both reliability and emissions compliance concerns. In addition, the vehicle developed a separate mechanical/electrical problem shortly after the NOx sensor failure. Because it involves different systems, I will file a separate complaint regarding that issue.