The National Highway Traffic Safety Administration (NHTSA) of the United States has launched a probe into model year 2011-2015 Ford Explorers over a possible exhaust leak.

A total of 154 complaints have been logged by NHTSA, each claiming that the odor of exhaust is strong inside the vehicle. Many owners also expressed concerns over exposure to carbon monoxide, which can be deadly.

Ford says that it is fully cooperating with the investigation, which could result in a recall if there is enough evidence to show a widespread problem. One crash has been linked to this issue, though no injuries were caused according to NHTSA. The total number of Explorers being looked at has not been divulged by the organization.

According to owners, the problem is particularly bad when the vehicle is at full throttle, when climbing steep hills and when the air conditioning is set to recirculate.

Ford has issued two different technical service bulletins about the issue, but owners have reported that a fix at the dealership did not make the exhaust smell go away.

Regardless, for 2016, the Ford Explorer has been refreshed inside and out, adding a more powerful base engine and a new top-of-line trim. Called Platinum, the new range-topping trim level combines luxuries and comfort not found in the Explorer Limited, along with the more powerful drivetrain that was previously reserved exclusively for the Explorer Sport. Think of Platinum as Ford’s answer to the GMC Denali lineup of vehicles.

There may not be a lot of space between the seat backs and the rear hatch, but the storage well is deep – deep enough to fold the power third row into it minivan-style.

And to access the cargo area is easy because the Explorer now has the hands-free power tailgate feature where you can just wave your foot under the bumper and automatically open the hatch.

Inside, second-row passengers enjoy more legroom with 39.5 inches of stretch-out space. People relegated to the back row still get 33.3 inches of rear legroom, which isn’t bad. This is one of the few three-row crossovers where I can actually fit in the back row, as headroom is ample and the seat cushion is set to a proper adult height. The downside is the third row only seats two people, unlike some competitors that can fit three passengers back there. This limits the Explorer Platinum’s seating capacity to six, as the second row features a pair of captain’s chairs.

But it’s up front where the real pampering of the Platinum Explorer takes place. The front seats, instrument panel, armrests and upper door trim are all finished in Nirvana leather and no, that doesn’t mean the pattern is flannel and denim.

Real aluminum and real wood can also be found in here and for the first time ever, a brushed-aluminum Ford oval is stuck in the middle of the steering wheel. The refreshed interior isn’t too busy and I like the overall constrained design.

As I headed toward Yellowstone National Park, a few straight highway sections allowed me appreciate just how quiet the 2016 Ford Explorer is. Ford claims this is the quietest cabin of any vehicle currently in the brand’s lineup and I can’t argue that fact.

The long highway stretches also let me sample the vast amount of driving technology stuffed into the Explorer Platinum. Although I didn’t get to try the active park assist, I did get extensive use out of the adaptive cruise control, which I have always been a fan of in the Explorer.

It behaves a lot like a human driver would and lacks the jerky braking and accelerating found in some other manufacturer’s systems. Ford has also outfitted a lane-keeping system in the Explorer Platinum that can be customized to the driver’s preference. The amount of intensity can be adjusted as well as whether the system sends out just an alert, an assist or both. With full assist activated, the Explorer would gently nudge the steering wheel to help keep the vehicle between the painted lines.

But the best feature of all has to be the built in washer jets for the front and rear cameras. Anyone living in the slushy snowbelt knows how quickly these cameras get covered in grime during the winter months, rendering them useless.