Sidney Wiley, who performs under the name Psyco Sid, was stopped for a traffic violation around 4:30 a.m. Thursday in the 1800 block of Barker Cypress Road.
Deputies found 10 bottles of what is believed to be liquid codeine, also known as 'lean', along with a gun and one and a half pounds of marijuana in the vehicle.
Wiley was arrested on an open felony warrant for possession of a controlled substance and more charges may be filed.