Would I be wasting my time to add extra grounds for the CAS? I see in the diagram it is using a common ground, would connecting it to the engine grounding point or to a chassis grounding point be worth while or a no benefit diversion?

 

I honestly don't see the point unless you have a sketchy ground, and in that case I'd just fix the common ground.

 

I had grounding problems on my OEM coil that caused random missfires to the point where I couldnt drive the car... but never any CAS problems that I know of, and hell you remember seeing my CAS plug...its half broken.

 

Yeah, I remember that ******.

I was finishing the wiring on the chassis amphenol for my car and discovered I was missing that ground wire (must have gotten too carried away thinning the harness) so was trying to decide if I should just tie it back into the common ground circuit. I think I'll just tie it in where it is supposed to go.

 

Sensors are ideally grounded back to the ECU's sensor ground pin.

 

Get a voltmeter and check? See if there's any voltage between the CAS ground and another grounding point? I'd suggest the big ground beside the throttle body.