I noticed what remains of a ground wire that comes out from under one of those protective pannels around the back of the car, almost parallel with the differential. I'm not entirely sure what it goes to, as the wire is demolished and I don't see anything nearby it could go to.


Anyone know what it is? I looked in the service manuals and didn't find it.

I can attach a pic if need be.

 

It's likely for grounding the exhaust. It normally slips over one of the bolts at the flange between the cat/midpipe and the cat-back exhaust.

 

Do attach a pic, but I think I may have had the same thing as you. Mine was from the underbody to the aluminum brace back there. I replaced it with another wire, but I'm not quite sure what the point of it is since the brace is bolted into the underbody.

 

I hooked mine back up...

 

Yeah I wrote that as if I had removed it but it's still there, I just replaced the wire since the original strap had snapped.

 

Why would the exhaust need a ground?? I'll try to hook it back up, but we already have most of the stuff underneath bolted up in the way. If I can't hook it up, is it going to cause a problem?

 

O2 sensor feedback ground loop

tom

 

Just another ground that once it dissapears puts more of a load on one of the other grounds. This is one that when hooked up helped lessen the 3k hesitation on my car.

 

^Yep. When I bought my car this wire was disconnected. Just reconnecting the old worn-out wire made a difference with my hesitation. Replacing it really seemed to help.

 

OK in that case I'll hook it back up. Thanks

 

I'm on a PFC with no O2 loop, but I think I should find a way to attach this to my 3" hi flow cat and RB duals...

 

^It doesn't hurt, but I don't think you'll see any difference with no O2 feedback. That said, these days I'm also on a PFC, open loop and even with the same exhaust. Mine's still hooked up out of habit.
There also another ground you might check back there. There's a ground block with a 10mm bolt for the fuel pump inside just under the hatch latching mechanism. I think cleaning that's a good idea.

 

This is anecdotal, but on the FC I noticed that cars that didn't have the ground hooked up were more likely to have rust problems with the exhaust. I think having it ground could help with that. If you have an all stainless exhaust it's moot, though .

I have an all stainless exhaust and no 1-wire O2 sensor at all on my car and I still have it connected .

Dale