'99 Q bad knock sensors, really?

[jfachatz]

I removed my driver's headlamp in my '99 Q45t to repair a cracked edge with silicone and in the process had to remove the air filter box and several items around it. One was a braided metal grounding wire coming from somewhere on the driver's side of the engine to the chassis. Everything else went back in without questions and was working fine for a day or 2 when the SEL popped and and has remained continuously on ever since. The ECU says both bank's knock sensors are now bad and it retarded my timing-killing the engine's performance. My Questions: Where should the braided wire be connect to the chassis? Could this wire being connected in the wrong place trigger a false reading by the ECU? Thank you!