Sensor in Engine Compartment - What is this?

[NSX-Files]

Curious - what's this thing on the firewall directly above the engine coolant tank cap in this pic?

 

[bngl3rt]

I think it's a chassis ground for some electronics.

 

[chudson1549]

Hey Dave it's an engine ground like bng said but for no exact electronics. It's just like the one near the alternator.. It should bolt to the valve cover acorn nut

 

[shawn110975]

100% correct engine ground, there is another one under the airfilter box that goes from the starter area to the frame rail,

then there are 2 in the front of the car and one in the trunk