[Madness!]

I've been getting CRAP gas mileage for months but I did look beneath once and noticed this wire had frayed off. What is it for? What is it called? I don't' see a sensor (just a bolt) attached to it, and nothing I've read online shows an oxygen sensor at this point on the vehicle. Could it somehow be a grounding wire?

 

[Pilgrim]

Looks like a ground strap to me. Perhaps someone has a better answer.

 

[deeman]

A braided ground strap between the exhaust system and the frame. Mine was rusted away too, for good reason being where it was located. I replaced it with a new strap and it made absolutely no difference.

*edited spelling mistake

 

[Wolfgang Huang]

I believe the ground strap is there to reduce the noise in the O2 sensor reading.

 

[chidog]

X3 its to ground the exhaust system.