3 failed flex fuel sensors? im lost

supercharged ls2 on 411 pcm with 2002 suburban flex fuel tune.

My car was running great and then I put Granatelli coils on there and thats when it went down hill. Anyway my car started to run a little lean and I looked at my ethanol content sensor and it was reading 37.6%. I looked at my tune and that is the default percentage when the sensor fails. I bought a new sensor hooked it up and the sensor immediately read 100% ethanol. Then seconds later it slowly falls down to 37.6% ethanol again. At this point I reach my hand in the engine bay to mess with the sensor wires and I get shocked. Long story I got rid of the coils and put my original ones back on. So I assumed the coils were arching or something and fried the second sensor because they're somewhat close. Bought a third sensor and it did the same thing. 100% then slowly down to 37.6%. Ive checked wiring ground is good. Power wire shows 12v. Signal wire shows 5.07 volts. Any ideas

So I have run those coils for 3 years now. No issues. Not saying you did not or could not have a bad one but I do not believe they are the root cause of the issue. I have a sensor on mine as well. This is a wiring issue.

In order to shock you, your body had to provide a better path ground path or it was holding the current imbalance. There had to be a built up charge that charge can either be yours or the cars. This is a imbalance in potential. Grounding issue?

spark created with Gap between 60mm spheres
volts
0.5mm - 2850
1mm - 4350
2mm - 7350
3mm - 10350
4mm - 13350
5mm - 16350

Thanks for the reply. Ill check all my grounds. I must have moved something taking those coils on and off .

A ground cable on the back of my drivers side head sheared off. This was probably the culprit of the shock. (tried to add a picture, i don't know if it went in or not). I don't know if this was causing the problem for the sensor yet.