Cylinder MIsfire - Experts help, please!

The scanner indicates "#6 CYLINDER MISFIRE".

I replaced the sparkplug and sparkplug wires on that cylinder and checked the contacts in the distributor cap. Yet, I continue to get the same message.

I would greatly appreciate any advice or theories. Clogged injector?

Thanks!

Have you noticed any pinging?

Year and engine code?
Is the cylinder actually missing?
What is the miss fire history readings like how many miss fires on that cylinder or any other cylinders missing?
Any other codes?
Did you clear codes and retest?
What brand of spark plugs are you using?
Got compression on that cylinder?

I had the same problems with my 97 305 vortec, after new plugs, wires, distributor cap and button didn't help, I was told to add a fuel additive called Chevron w/tectron to the fuel tank. I ran this additive thru 2 tanks of fuel and my miss was gone, (dirty injectors?). This may or may not be "your" problem but it fixed mine, just wish I had done this before the 150$ tune up.

what did the plugs look like? especially #6