duoyan

1. your gasaline cap is not tight. Retight it.
2. some leakage, such as air condition system
3. computer .
4. transducer.
5. valves

In one word, very complicated situation.

solution:
Follow your manual to do some basic check and adjustion. If it does not work, you have to go to dealer. Canadian tire often cannot find the exact problems and solve them because they do not have some special tools. Check engine light shows that the computer system finds problem with your car. THough the problem may not be serious, but mostly only dealer can find out what it is. THough you can drive smoothly right now, but you will have trouble someday if you do not fix it because computer controls your car.