So my engine light keeps coming on every time my fuel gets to half tank, I checked the code and it is for the emission. Last time it came on at half tank I just left the light on and it turned off once the fuel got to quarter tank. I have no idea what would cause this, any help would be great though.

 

There is more than one 'emission code'. Telling us the exact code will help you out.

 

If I remember correctly it was P040 or something like that.

 

i have the same issue with my 1996. been in shop numerous times and no 1 can figure it out. I just use the scanner to shut off the light

 

I do the same thing, I am probably replace the gas cap and see if that helps

 

There are 4 numbers to every OBD2 trouble code, ex. P0406. Your missing one. Having the actual code will give some direction to your diagnosis.