Have noticed quite some time ago that the braided grounding strap (located downstream of the cat) had been torn off. Anyone know why this is even needed and if I need to replace it?

 

I have to guesses, depending on how big/thick the strap is, it could be back up exhaust support, or it could be grounding for the O2 sensors.

 

It's about a 1/3 inch in width. Seems like uninsulated braided steel strands. Those are good guesses though... sounds good to me.

 

I dunno what it is but I broke mine when I installed my y-pipe and never fixed it. It has been a year and nothing has blown up yet so I think i'm good.

 

...dangling from underneath the car...

I also damaged/tore it off during the Ypipe/RTcat install and tried to jerry/rigg it back up several times...keeps on falling down...

No problems ever.

 

No one is really sure what it is, but do a search for ground strap and you'll find some posts. Some say that it's a ground for the O2 sensor, and others think it just helps to ground the exhaust overall. You may also want to check for ECU codes. I found a code 1405 that doesn't trip the CEL, but is saved in memory. Since I replaced my ground strap the code went away. The 1405 ECU code is a 1999 code, but isn't even mentioned in the FSM.
Only one other member has ever gotten the code and he never figured out what it was either.
-hype

 

The ground strap on the muffler is called a bonding wire. You will probably find a bonding wire between the transmission & the body as well.

The bonding wire is NOT to ground the 02 sensors or anything. The bonding wire at the muffler flange end is to ground the exhaust and prevent it from acting as an antenna to pick up stray noise, amplify it and reflect to the radio.

In other words, to reduce noise on your radio reception.