Help I accidently cleared the engine codes

I cleared the codes (check engine light) before reading them now I would like to know exactly what I need to do to get the codes set again so I can fix whatever is wrong. I have heard of "Drive Traces" or "Drive Cycles" that basicly say drive the car like this for so many minutes then drive it some other way for so many minutes and it will run all the tests again and set the codes as necessary. Some emissions tests check these codes and if they have been recently cleared the car can not be tested until they are reset. Can anyone tell me exactly how to do this for my 1994 1.0 manual Metro?

Never mind I just drove around for about 10 minutes and the light came on.