Check engine light

Just bought a '92 G-20 conversion. After driving for about 20 miles the check engine light comes on. After 10 minutes or so it extinguishes. Also seems to be aggravated by pulling uphill (I live in western VA.) Any suggestions?

You need to pull the codes from the computer and see whats stored. It best to do it while the light is on. You can go by autozone and they will do it for free.

If its related to up hill, it could be a bad convertor. Do you notice a rotten egg smell if you stop after going up a hill? Convertor could be stopped up, but if it is there is probably something else wrong to cause it to stop up.