what would cause check engine light to come on in a 2000 chevy impala. car is...

[micwaltrip15]

...running great. ? Just passed New York state inspection with flying colors including emmisions testing. came on last week for a day and went off the next day. came on again this morning.

[l b]

Probably a vacuum leak. If there is an AUTOZONE close to you, they can hook up a computer and tell you what is causing the light to come on. It is usually a free test.

[Robert D]

A lot of things can cause this, this sort of light is just to bring something to your attention. For example, my son overrevved my motor on my Corvette. I had no idea such a code would latch. It served a good purpose, ratted on my son! It was reset at no charge at my local auto shop, they had a chuckle! You can purchase a device called an OBD2 at most auto shops, they are fairly easy to use and allow you to reset most of the fault conditions(codes) but not all, some latch on hard failures.

[terry t]

One of the simplest things to check is the gas cap. If it is loose, gas fumes escape are considered emissions. The check engine light will come on.

[jerseynshelby]

gas cap,oxygen Sensor,map sensor take it to auto zone