US ends probe into Ford fumes

FILE - Plant employees drive 2011 Ford Explorer vehicles off the assembly line at Ford's Chicago Assembly Plant in Chicago, Dec. 1, 2010. The U.S. government's road safety agency has closed a more than six-year investigation into Ford Explorer exhaust odors, determining that the SUVs don't emit high levels of carbon monoxide and don't need to be recalled. (AP Photo/M. Spencer Green, File)
FILE - Plant employees drive 2011 Ford Explorer vehicles off the assembly line at Ford's Chicago Assembly Plant in Chicago, Dec. 1, 2010. The U.S. government's road safety agency has closed a more than six-year investigation into Ford Explorer exhaust odors, determining that the SUVs don't emit high levels of carbon monoxide and don't need to be recalled. (AP Photo/M. Spencer Green, File)

DETROIT (AP) -- The U.S. government's road safety agency has closed a more than six-year investigation into exhaust odors in Ford Explorer passenger cabins, determining that the SUVs don't have high levels of carbon monoxide and don't need to be recalled.

The National Highway Traffic Safety Administration says it reviewed more than 6,500 consumer complaints, tested SUVs in the field and called in automotive, medical, environmental health and occupational safety experts before making the determination.

The probe covered nearly 1.5 million Explorers from the 2011 to 2017 model years. NHTSA said it received multiple complaints of sickness and crashes caused by the exhaust fumes that involved three deaths and 657 injuries. Many complaints came from police departments that used Explorer Police Interceptors as patrol vehicles.

But the agency said in documents released Monday that it used rigorous test methods to send exhaust gas into vehicles. No Explorers with bodies that were sealed under a 2017 Ford field service campaign had carbon monoxide levels that were higher than Environmental Protection Agency limits.

The agency, though, conceded that fumes had leaked into the Explorer cabins. "NHTSA recognizes that hypersensitivities to CO and other exhaust gas constituents exist within the overall population," investigators wrote. "However, the agency does not set limits or determine the adequacy of established safe levels."

The agency determined that sealing issues due to installation of sirens, lights, cages and other items in police SUVs were responsible for the highest measured carbon monoxide levels in vehicles it tested.