Illumination of the Check Engine Light can be caused by a loose or worn gas cap.Google+
Car Problem Reports
Chevrolet Aveo Check Engine Light Due to Gas Cap Issue
Chevrolet Aveo Problem
Average Mileage: 58,335 mi (24,000 mi - 128,000 mi)
Visitor, 2007 Chevrolet Aveo, 90,000 mi
Replaced gas cap. The check engine light stayed off for two wks. and is back on again.
There is a recall on this problem
Visitor, 2004 Chevrolet Aveo, 40,000 mi
I was overseas serving in the military when the recall started, by the time I returned the recall had expired.
Visitor, 2008 Chevrolet Aveo
replaced gas cap 2x
This started about 5 years ago at 25,000 miles, and all I have to do is to turn the gas cap at least 3 turns to make sure that the Check Engine light doesn't come on. If it does and it is shortly after you pump gas into the car, then you know that you haven't turned it past 3 turns on the gas cap. This problem hasn't happened to me since it started 5 years ago.
Visitor, 2006 Chevrolet Aveo
changed gas cap
Visitor, 2005 Chevrolet Aveo, 100,000 mi
worn gas cap caused engine light to come on. replaced cap and passed smog test
Made sure gas cap was tightened and it completed the problem. Gas cover fell off. Have noticed other with the same problem
Visitor, 2007 Chevrolet Aveo, 30,500 mi
Check engine light went on and the repair man said the gas cap wasn't locking so the gas fumes were not being properly cycled through the engine. I just had to get the gas cap replaced; it cost about $25.
Visitor, 2006 Chevrolet Aveo, 48,000 mi
put a new gas cap on