General Motors is recalling certain model year 2011 Chevrolet Express vehicles converted by Impco Automotive to run compressed natural gas (CNG), manufactured between November 23, 2010 and December 23, 2010 and equipped with a four tank configuration using a pressure relief device (PRD) and pressure relief vent pipe assembly
If a pressure relief device activates with an improperly assembled vent pipe, compressed natural gas may be vented into the passenger compartment. If an ignition source is present, an explosion or fire may result.