Check Engline Light b4 changing spark plugs

[Super Blue]

Hi All,
I was going to doing a oil change on my 96 a few weeks back, and decided it was time to change the plugs as well. So I opened up plug # 1 to check what sort of condition it was in and if it required change or not. Ever since then my check engine light has come on, and I had not even changed the plugs yet. I even unplugged the battery and left it d/c overnight and the light did not go away.
Since then since I am getting the check engine light, I changed the plugs regardless, and there is no signal that the car is running any better or worse compared to before.

BTW: I put in Bosch Platinum plugs.

How can I get the light to go away?

Thanks for any input you guys can provide

Super Blue

[foodaa]

You need an OBD II scanner to see why the check engine light is on. I think AutoZone will scan your car for free. Maybe you damaged the plug wires, crossed wires or something.