A Loose or worn gas cap may cause Check Engine Light to illuminate.
Car Problem Reports
Chevrolet Express 3500 Check Engine Light Due to Gas Cap Issue
Chevrolet Express 3500 Problem
Exhaust & Emissions Affected: Gasoline
Visitor, 2010 Chevrolet Express 3500, 110,000 mi
check engine light came in driving in IL IN and KY. Went back out when I got back to TX where it was alot warmer. Happened twice on diffrent trips into a colder climate. Turned out to be a bad gas cap...