1994 Metro Check Engine light on

My check engine light is on and I don't have a clue what's wrong. I have a scan tool but since this is a 1994 not a 1996+ I assume that the scan tool won't work. I hate to give the dealer half the Blue Book value of the car just to tell me what is wrong. Is there another way? I do know that it failed an emissions test recently. What would be the cheap and obvious things to fix? Oxygen sensor? Is there a way to test the Oxygen sensor directly? EGR valve? I see that mentioned here alot will that set off the check engine light? I just got this a couple of weeks ago and I don't have it licenced or insured yet. To get it tested I would need to pay to get it registered and insured then pay for the test, that would probably add up to more than I paid for the car.

Get a Haynes manuel from Autozone it describes the codes as well as how to get them. Basically you pull a spare fuse and put it in a diagnostic port on the fuse block under the dash. The check engine light will then flash any engine codes. The only one I know off the top of my head it 13 which is a bad O2 sensor the manuel will have the others.

not sure how to check that but i was reading through the manual on how to check the engine codes but before i did i tried starting it up again and i noticed that i am not getting any check engine light or anything from the dash any ideas on that?