Ford has been urged by a prominent automotive safety advocacy group to recall 1.3 million Explorers from 2011 to 2017, which could have carbon monoxide leaks.

The Center for Auto Safety claims that the National Highway Traffic Safety Administration (NHTSA) has received at least 1381 complaints from Explorer drivers and passengers about exposure to carbon monoxide.

Concerns about carbon monoxide leaks in Ford Explorers first emerged when complaints about the Police Interceptor Utility model were published. The automaker swiftly issued a voluntary ‘customer satisfaction program’ to repair the police units but stopped short of calling the move a recall.

In October, Ford issued a ‘complimentary service’ notice to Explorer customers, offering to service all 1.3 million vehicles to reduce the potential for exhaust gases leaking into the cabin. The safety group doesn’t believe this move goes far enough.

“Since some Ford dealers are responsibly replacing cracked exhaust manifolds, it is time for Ford to take a more serious step, recall all of these vehicles, and inspect and replace cracked exhaust manifolds,” executive director of the Center for Auto Safety, Jason Levine, said.

Despite this, Ford remains insistent that the Explorer is safe.

In a statement, Ford spokeswoman Elizabeth Weigandt said, “Ford’s investigation and extensive testing has not found carbon monoxide levels that exceed what people are exposed to every day.”

“The safety of our customers is paramount. We encourage customers with carbon monoxide concerns to bring their vehicle to their local Ford dealer for a free service designed to reduce the concern. If they are not satisfied with the service, we encourage them to call our dedicated hotline at 888-260-5575.”