A Loose or worn gas cap may cause Check Engine Light to illuminate.Google+
Car Problem Reports
Chevrolet Tracker Check Engine Light Due to Gas Cap Issue
Chevrolet Tracker Problem
Average Mileage: 113,809 mi (58,000 mi - 161,356 mi)
Visitor, 2003 Chevrolet Tracker, 161,356 mi
gas cap makes the check engine light come on. bought new cap worked for two days now its back on after I refuel.
Visitor, 1998 Chevrolet Tracker, 140,000 mi
replaced the gas cap and the code went away. Cheap fix!
Visitor, 2001 Chevrolet Tracker, 58,000 mi
Tires Plus reset the warning light after a diagnostic test showing that it was the gas cap. 1 1/2 months later I am stranded when the fuel pump goes out. Coincidence???
Visitor, 2002 Chevrolet Tracker, 127,000 mi
Check engine light was diagnosed as gas cap. I replaced it..Drove for one day now check engine light is on again
Visitor, 2004 Chevrolet Tracker, 99,000 mi
Same check engine light.
Visitor, 2002 Chevrolet Tracker, 97,500 mi
Computer sensor "check engine" light came on. Local auto part store computer check stated " to check gas cap". Sensor light went off.