GM has updated a service bulletin covering exhaust odors inside 2025–2026 Silverado and Sierra HD trucks equipped with the L5P Duramax. A leaking EGR cooler bypass valve shaft seal may be responsible, and technicians may also encounter DTC P2463.

General Motors has launched a new emissions recall that affects certain 2024 Chevrolet Silverado HD and GMC Sierra HD trucks equipped with the 6.6L L5P Duramax. Recall ID: N242438500 Title: ECM OBD – Selective Catalyst Reduction (SCR) Fault Detection Release Date: November 2025 Applies To: 2024 Chevrolet Silverado 2500HD / 3500HD (L5P 6.6L Duramax) 2024 GMC Sierra 2500HD / 3500HD (L5P 6.6L Duramax) This is a voluntary emissions recall focused on the software that monitors