Check engine light is always on and want to get it to go away

You should post the codes. I think you need a smoke test on the EVAP system to find the leak.

Just dealt with this.. i tried the gas cap and nothing changed. I ran an instrument in my o b d port and it read evap emissions. Try your purge valve and switch to a higher octane gas. Secondly, quit using your cosmetic circuit 12v. Because it throws off the polarity and causes the diodes to capacitor to work too much but enough throw off the ECM. I quit using mine and CEL went right off