2000 Chevy Silverado Computer not telling cylinder 2 to fir

I recently changed all of my spark plugs. After doing so, my service engine light came on, so I used a computer diagnostic tool to try and figure out why. It said "random misfire cylinder 2". Thinking I may have had a bad spark plug cable or bad coil pack, I also changed those. The service engine light is still on, I used the diagnosis tool again and it is still saying random misfire on cylinder 2. I checked the spark plug and it seems fine, even bought a new set and exchanged them, the service engine light still comes on and the diagnostic tool still says the same. What could be going on?