South Korea has opened an investigation into possible exhaust fume leaks inside Ford Explorers amid the U.S. National Highway Traffic Safety Administration(NHTSA) probe into the allegations.

The South Korean Ministry of Transport on Friday revealed its probe into the American SUV.

Reuters said that Ford has come under investigation by the NHTSA, after 154 complaints about exhaust gas odors were filed by owners of Explorers from the model year 2011 through 2015.
 
Market researcher Auto Data estimated that more than 950-thousand units of Explorers produced during the period have been sold.
 
The U.S. traffic watchdog said that the problem becomes worse when the SUV is running at full throttle, such as ascending a steep hill. The use of the air conditioner in recirculation mode also makes the problem worse.