What does this wire do anyways? I know it grounds something but what?

 

The exhaust system ground wire discharges the static electricity that occurs from the exhaust gases flowing through the pipe.

 

Seriously?

 

And that helps us how?

 

Static build up does nothing good. Some of the control devices operate at very small voltages. Maybe a build up could cause some radio interference, etc.
There could be some safety factor when pulling up to gas pumps, etc. too. Very remote I would think, but why chance it for the sake of a wire.

 

Can anyone confirm this? This is now getting interesting.

 

Even if you don't have a grounding kit, look how many grounding points on the vehicle, look how many just under the hood!
The exhaust is just an extension of the engine, and to be sure there is adequate metal to metal when the exhaust is connected, they ground it to to a common chassis ground point.
That's the logic behind grounding. As far as the 'whys' I think we need more info. But reducing electrical noise is usually the main reason.

 

if it's grounding the exhaust I'd have to say it's for the o2 sensors. it just helps them read better.

 

Good point!