Fiat Chrysler Automobiles (FCA) could recall around 1 million vehicles due to issues with its 2.4-liter Tigershark engine. The company will most likely recall Jeep SUV models, which are equipped with the engine.

The Detroit Free Press reported that in a regulatory filing, FCA claimed that the engine could be a danger to the environment. The release of the excess tailpipe pollution was identified during testing of the vehicles.

“In connection with internal testing, we determined that approximately 1 million vehicles equipped with the 2.4L Tigershark engine may have excess tailpipe emissions,” FCA stated.

In a company statement released by spokesman Eric Mayne, Fiat Chrysler Automobiles revealed that they have been communicating with the California Air Resources Board and U.S. Environmental Protection Agency after becoming aware of the issue. However, it is unclear how dangerous these emissions could be.

“FCA has been working closely with EPA and CARB, and we continue to do so, on a group of vehicles equipped with Tigershark engines. As this population ages, some vehicles exceed in-use emission requirements, depending on drive cycle and mileage,” the statement read.

“We are conducting test programs to define a remedy, which also requires approval by the agencies. Affected customers will be advised when service becomes available, and will be provided free of charge. This is not a safety issue and there are no enforcement actions.”

Fiat Chrysler Automobiles’ potential recall is reportedly based solely on the tailpipe emissions and not the lawsuits that claim the 2.4-liter Tigershark engine burns excessive amounts of oil, which could result in the vehicle stalling. The company has not announced when the recall will happen.

Jeep Grand Cherokee
Jeep Grand Cherokees are pictured lined up. Reuters/Eduardo Munoz