The National Highway Traffic Safety Administration (NHTSA) has closed its investigation of the 2011-2017 Ford Explorer. The agency examined claims that exhaust fumes entered the passenger compartment in both the consumer model and the Police Interceptor. However, the NHTSA ultimately decided that the automaker did not need to issue a recall regarding this complaint.
The agency pointed to two causes of the smoke: inadequate crash repairs on consumer cars and poor installation of aftermarket upgrades on Police Interceptors. According to an agency summary on January 17, “Throughout the investigation, accurately measured vehicles with higher levels of carbon monoxide were almost invariably affected by changes, damage, or other causes that damaged the rear passenger cabin seals.”
Police Interceptors are often subjected to upfitting, a process that adds sirens, lights, cages, and other equipment to vehicles for law enforcement and first responder duties. Sealing problems associated with this additional feature were “responsible for the highest carbon monoxide levels measured in the test vehicle,” said the agency’s report. It was a similar case with consumer models, with agents typically tracing the source of exhaust fumes to repairs to rear defects that “did not ensure sealing integrity.”
NHTSA studied the matter 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 collaboration with Ford and other entities while reviewing more than 6,500 consumer complaints.
During the NHTSA investigation, which originally started in 2016, Ford issued Field Service Actions (FSA) to both Explorer models that resulted in measurable reductions in CO levels. Ford and NHTSA tested the automaker’s latest, which asked to reprogram the HVAC system, and saw a “substantial reduction in CO levels.” In 2017, Ford said it would service the Police Interceptor with an aftermarket installation, inspect the seals and perform repairs free of charge.
The agency even conducted a blood test to measure passengers’ CO levels. However, the agency concluded, “Additionally, even without FSA repairs, no vehicle unaffected by upfitter issues or damage from previous accidents was identified with CO levels that exceeded acceptable CO exposure levels.”