2003 Buick LeSabre check engine light

Every time I fill up my tank or my gas runs low I run into the same Evap Code issue as a check engine light.

Between the 3/4 tank and 1/8 tank, the lights gone and I haven't had a single problem in the performance. But Smog time is coming, and I know this light is gonna show up on the reader.

Any ideas?

 

Welcome to the forums.

You need to see what codes are set into memory and then work towards repairing them.

 

P0440 and every time I look it up all I find from people is that I should replace the gas cap. I have replaced it several times, including one from GM and high performance and the current AC Delco on it.

 

P0440 = Evaporative System Malfunction, Large Leak

When your vehicle is started there is a vacuum placed on the fuel vapor recovery system which includes the fuel tank for ten seconds. Then the vacuum valve is closed and a sensor monitors how fast the vacuum in the system decays or is lost. If it's too fast it knows there is a large leak and alerts you with a P0440 code. This test is only performed when the fuel level is between 15% - 85% of full.

The gas cap is only one cause of the problem. If you've replaced the cap.... that is not the problem.

With the age of your vehicle I'd guess you have a cracked or broken vacuum hose.
Another possible cause is a crack in the fill line or the vent line on the filler neck.