Check engine light stays on after car is turned off?

i have a 2002 sunfire gt with a 2.4 engine. i turn off the car but the check engine light stays on. i will turn on the car and it will go away until i get to about 25 mph. then when i stop at the light, it will be gone. i have tried tighting the gas cap and everything. can anyone help with my problem???

u try disconecting the computer and letting it be for 10 seconds then click it back in place

Disconnect your battery for about 15-20 minutes to clear this light. If it comes on again when you reattach the cables, you may jus have a shorted light. While it is on, take it to a local auto parts store. A lot of them will read error codes for free and tell you what could be wrong. Take a look in the engine compartment and see if you see anything loose or dangling.