The National Highway Traffic Safety Administration (NHTSA) has closed its investigation into the 2011-2017 Ford Explorer. The agency investigated claims that exhaust fumes entered the passenger compartment of both the consumer model and the police interceptor. However, NHTSA ultimately determined that the automaker does not have to issue any recalls related to these complaints.
The agency pointed to two causes for the fumes: insufficient repairs in consumer cars and improper installation of aftermarket fittings in police interceptors. According to the agency’s January 17 summary, “Throughout the investigation, vehicles accurately measured with higher levels of carbon monoxide were almost always affected by modifications, damage or other causes. compromising the rear passenger cabin seals.”
Police interceptors often undergo retrofitting, a process that adds sirens, lights, cages and other equipment to vehicles for law enforcement and first responder duties. Sealing issues related to these additional features “were responsible for the highest measured carbon monoxide levels in the test vehicles,” the agency’s report said. It was a similar case with consumer models, with the agency typically tracing the source of the exhaust back to rear-end collision damage repairs that “did not guarantee waterproof integrity.”
NHTSA studied the problem for six years, incorporating expertise from the automotive, medical, environmental health and occupational safety fields into its investigation. The agency also conducted field inspections independently and in cooperation with Ford and other entities while investigating more than 6,500 consumer complaints.
During NHTSA’s investigation, which began in 2016, Ford issued Field Service Actions (FSAs) for both Explorer models that led to measurable reductions in CO levels. Ford and NHTSA tested the automaker’s latest, which called for reprogramming the HVAC system, and found “a substantial reduction in CO levels.” In 2017, Ford said it would repair police interceptors with aftermarket facilities, checking seals and making repairs at no cost.
The agency even went so far as to perform blood tests to measure passengers’ CO levels. However, the agency concluded: “Furthermore, even without FSA repairs, no vehicles not affected by fit-out issues or damage from a previous accident have been identified with CO levels exceeding the levels of Occupational exposure to CO allowed.”