Warning light 1998 Corsa s reg - automatic?

The other night when I was driving home, my car's engine warning light came on & I lost all power, managed to get it started again but only by revving it permanently. Diagnostic machine showed code for misfire, and I was advised to try new spark plugs, we have now replaced spark plugs, leads & coil pack, all of which have made a huge difference & the car now starts no problem. However the warning light remains on - any ideas?