Holley sniper install

Just a little follow up here. I got the system up and running. But it wasn't quite right. I kept seeing a little bit dirt voltage signal. So I changed to the recommended NGK plugs and traded out my plug wires for the recommended type. Those are the only changes I made. I learned long ago. One or two changes at most at a time. If something the wrong direction happens you can backtrack to the source of the problem faster. Normally. Want to guess what happened? **** got worse. So this is where I clarify. Follow directions. Now I thought I did. Sort of. I had taken the grounds and attached them to a body grounding post that I have under the firewall (inside the cabin). Which is specifically designed for a ground point. Then I ran a 2awg from that post directly to the battery. Nope, don't do it, wouldn't be prudent. It created a dirty ground point for the ECU and gave it fits. Now why did changing the plugs and wires exacerbate the problem. I have no idea. So I removed the wires from the post and connected them directly. Which makes a direct connection straight to the battery. Which it did before also. At least in my mind it did. Now we have one less issue thank goodness. The point I guess is: don't try to out think the engineer that designed the damn thing in the first place. Do what they say and you wont have to chase your own tail so much.