Ok, I talked to the previous owner tonight. Seems though he didn't change the opti or cap and rotor. All he changed was the Plugs and the coil. That didn't help obviously. The wires also look in really good shape. So I might be pulling the water pump and checking the cap and rotor. Also, I noticed that my intake elbow is shot to complete Hell. Looks like the backfiring did its number to it.