Spark knock on 93 octane?

[acsho]

I am getting noticable spark knock under light load even though I am using 93 octane gas. I have no codes, could the knock sensor go bad without a code?
I also removed the plugs and they have a reddish tint to them is this normal? I have never seen this on a plug before, just the normal carbon. I am running Autolite double platnium plugs. I have no mods to the engine.

 

[Storm-Chaser]

Pull the codes. If the Knock Sensor has failed it should set a code.

 

[Kens1992mtxSHO]

Start with checking codes first, but also check the condition of your wires at the boot. One of them may be cracked causing the spark to arc.

 

[SHOZ123]

You've got maintenance issues. Probably a lot of blowby. This will lower the effective octane rating of the fuel.

Depending on what processor you have the KS doesn't do much anyway in stock form.