Engine Misfire 1997 Ford Taurus

Ford Taurus

“Service Engine Soon” light comes on all the time on my 1997 Ford Taurus GL single 3.0 L OHC. Code reader indicates Clyilnder 6 is misfiring. I inspected all plugs. They all needed to be changed so I changed them with OEM plugs & also wires. “Service Engine Soon” light ciontinues to be on.comes on.

What else could it be?

Thank you

This was for a newer Taurus but still applies: https://www.freeautomechanic.com/mechanic/forum/2016/07/p0300-ford-taurus-2006