An automotive safety advocacy group has once again called on Ford to recall 1.35 million Explorers over concerns of carbon monoxide leaks.

The Center for Auto Safety asserts that it has found 44 recent complaints about fumes and potential carbon monoxide in a government database. It is claimed that the owners responsible for these complaints had already taken their Explorers in for repairs as part of a Ford customer service campaign that commenced in October, The Detroit News reports.

If this story sounds familiar, that’s because it is. Back in January, The Center for Auto Safety called on Ford to recall all 2011-2017 Explorer models over potential carbon monoxide leaks. The automaker failed to do so, insisting that the ‘complimentary service‘ notice it issued to Explorer customers to come in for free repairs was adequate.

The case isn’t yet closed.

The National Highway Traffic Safety Administration has been investigating the issue for more than two years but has yet to reach a conclusion.

Executive director for the advocacy group, Jason Levine, says that based on the complaints seen, the carbon monoxide issue still exists in 2018 Explorer models.

“The continued complaints and corresponding reports of incidents and injuries demonstrate the problem of carbon monoxide exposure inside Ford Explorers has not been resolved,” he said.

In response, Ford says that the popular Explorer SUV is safe, the free service has addressed any exhaust odors and that owner complaints have decreased.

In January, Ford also stuck to its guns and insisted that there was no cause for concern.

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