A Howick Township man faces several charges, after an investigation by OPP at a RIDE checkpoint just outside Wingham.
Police say open liquor and marijuana were seen inside a sports car that pulled into the lane in the early hours of last Saturday morning.
Investigators say a second breath test at the Walkerton detachment confirmed officers' suspicion that the driver was drunk behind the wheel.
The 19 year-old is charged with having a blood-alcohol content above zero, marijuana possession, having an open container of liquor in the vehicle and two Highway Traffic Act offences.
His licence was also suspended for three days.