DETROIT — About 1 million Fiat Chrysler vehicles with four-cylinder engines in the U.S. may spew too much pollution, and the company is working with government officials on a recall.

Fiat Chrysler says in a quarterly filing with securities regulators that it found the excess pollution during internal testing of vehicles with 2.4-liter “Tigershark” engines. The engines date to at least 2013 and are used in several Jeep SUVs as well as some cars.

FCA says it's working to identify the affected vehicles and develop a repair.

The vehicles and model years covered by the recall were not listed in the filing. The engines are used in current versions of the Jeep Compass, Cherokee and Renegade SUVs as well as the discontinued Dodge Dart compact car and Chrysler 200 midsize car.