Illumination of the Check Engine Light can be caused by a loose or worn gas cap.
Car Problem Reports
Pontiac Montana Check Engine Light Due to Gas Cap Issue
Pontiac Montana Problem
Average Mileage: 131,864 mi (79,000 mi - 280,000 mi)
Visitor, 2006 Pontiac Montana, 200,302 mi
light just will not go away no fix
Visitor, 2001 Pontiac Montana, 120,345 mi
Check engine light comes on due to loose gas cap
Visitor, 2007 Pontiac Montana, 82,000 mi
just bought this two days ago, gas cap message came up yesterday, light came on today for check engine and the gas cap light is still on. going to try to replace the gas cap and see if it fixes it
Visitor, 2004 Pontiac Montana, 102,000 mi
not fixed..just tighten the cap well each time it is opened
Visitor, 2005 Pontiac Montana, 112,000 mi
I have had to replace my gascap several times over the last few years. It gets frustrating and expensive.