engine light on-- dealer claims a gas vapor leak causing the problem?? comments please

 

try getting the problem code that is being thrown. some people on here are walking encyclopedias of check-engine-light (CEL) code knowledge.

 

Go to Auto Zone or Advanced Auto and they will tell you what code has been generated and what it means.

 

Evaporative emission system leaks are the most frequent reason for MIL's. It can be as simple as the gas cap not being tight enough from your last fill-up. If the code description is for a small, med, large, or gross (meaning massive) leak, then the gas cap and all hoses are checked. Any other code for evaporative emissions is related to component failure.
Just a history note for all noobs: since the dawn of internal combustion engines, the fuel vapors were vented to the atmosphere whenever you turn your car off. Well, the tree huggers said that stuff is ruining our atmosphere and must be contained. Soooo, now systems are on cars to keep those vapors locked up until you start the car again, and get used up at that point.
Nice of the treehuggers to make everyones car more complex, heavier, and expensive, isnt it.

 

When the car is not running, the rear solenoid is opened (NO) to the atmosphere to allow for air to be vented during fill up.

When the gas cap is put back on and the engine is started the rear solenoid (NO) is closed and a vacuum is pulled sending any vapors to the intake and burned during combustion.

If you have a vacuum leak there could be 2 causes. 1. your gas cap is not sealing correctly or 2. The rear solenoid may not be closing properly.

Either of these two could cause a vacuum not to be pulled by the engine. Performance will also suffer. (vacuum leak)

I have not included hoses of any type due to the newness of the car. Could be though!

In any case a CEL will be set.

 

The evap system consists of a canister,canister cut/drain valve,fuel tank,lines and finally a purge solenoid. If any of these are bad then you can set an evap code. At the dealership I have seen all on 20k mi or less go bad. Good luck. A gas cap is your most common,if not then more than likely the canister cut valve is your culprit due to it's location. Attached to the bottom side of the spare tire well where all the dirt and debris can get to it.

 

go to a garage and have them test your gas cap for leaks...

If the gas cap passes, then you need to have someone (shop) run a "smoke test"...they will fill this purge system with a smoke that is visible to the human eye, and once the system is full, it will begin to blow the smoke out of where the leak is...

This will then tell you exactly where your problem is...and yes, most commonly its the gas cap not getting tightened down last time you gassed up...

However, if it was the gas cap; if you corrected it, the light would turn off...sounds to me like you got something else going on, so id get it smoke tested.