hi i own a 2004 malibu. on my radio it says "check gas cap" but there is nothing wrong with the gas cap (i think this is because i accidently poked a hole next to the gas cap). also, my engine light is always on and i have to give a little gas everytime i start it up. it seems like gas isnt getting to the cylinders or something (other than when i gas start it). does anybody know what the problem(s) could be?

thanks in advance!!

 

I had a similar problem. A bad filler cap.
System is pressurized so any leak will be informed by computer and the pcm will alter calibrations to compensate.Also a problem code will be stored.
A new cap($10) and reset dtc.
Seal up the hole puntured if the cap will not seal it.