I think I'm to blame for this problem

A while back ago we had a big snow storm, I went out to move the car and she started fine, she was stuck in the snow, so I rocked her back and forth in reverse and drive, and then the motor started vibrating and had hardly any power. I got out and looked undr the hood and the engine was completly covered in snow....oops.
I'm figuring it's a coil pack problem, that one of them shorted out. Theyre easy t get at as theyre on the drivers side of the engine and right up top. My question is, how do I know which coil pack is not working ? AND, If I recall correctly from my old sunbird, theres 2 coil packs, and underneath them is a ECU or some sort of electronic device ?
Any advice ? I'm trying to save a chunk of money from a tow and a dignostic, I figure I might be able to fix this myself ...if I diganse it correctly.
Sorry, I forgot to mention one last thing..I read somewhere you can use a multimeter and check the resistance on the coil packs ? I cant find the site anymore, But if i take off both coil packs, and check the resistance in both of them, shouldnt they both be the same ?
Ok, I just took the spark plugs of the coil pack numbered 1-4, and there was no spark on them. So I'm guessing that particular coil pack has failed.........................OR...it could be the module ??
I seemed to have solved this all by myself lol
I bought a new coil and the cars alive and running

The only odd thing is the check engine light is still on....it was on when she wasnt running well and only firing off 2 cylinders.
You'd think it would go away since the problem is fixed ?