im thinking about buying a 2008 cobalt ss the guy says its the key ignition it will crank but not start and he says the key sticks and it will keep cranking.

He also says the check engine light is on and autozone told him it is a sensor to do with his emissions im figuring a oxygen sensor.

Thanks guys

 

Ok, you can buy it then.

 

Could the key ignition be the problem or something more serious?