MACK issued a recall on the CXU, LEU, and MRU models

On certain vehicles equipped with Cummins compressed natural gas engines, incorrect engine ECU programming could cause the exhaust system temperature to become elevated during cold weather operation. This could also cause flames to be emitted from the exhaust. As a result, nearby combustible material could be ignited, increasing the risk of a fire, injury and/or damage to property. Correction: Authorized Cummins service facilities will update software programming.