Me and my friend put long tube headers on his 96 Z28. We put pacesetter coated long tubes, with y-pipe on. We used brand new AC delco O2's with caspers o2 extentions for the front, and caspers o2 simulators for the rear.

We got them in no problem and hooked every thing up. It started right up and everything was fine. On his way home the SES light came on so we brought it back to the shop and scanned it. It said no data from the bank 1 sensor 1 O2 sensor. We looked at it and it looked like one of the wires was mlted. We called my supplier back up and they sent out another one, thinking it was the o2 sensor was at fault. We hooked it up and as soon as we turned the key on we heard a pop, and an electrial buning smell. we looked under the car and the same thing happened.

I took some pics with my phone (they are not the best quality) but i have no idea what is causing this.

http://home.rochester.rr.com/a001cars/images/o2_1.jpg
This is the connector side of the o2, the wire was auctually seperated, and the piece hanging off to the left is auctually just the plastic coating over the wire, there is no metal wire inside anymore

http://home.rochester.rr.com/a001cars/images/o2_2.jpg
This is the sensor side of the wires. One of the wires has "shedded" its protective plastic skin. You can see the plastic seperated at the top, and the wire it came off of is right below it.

http://home.rochester.rr.com/a001cars/images/o2_3.jpg
About midway up the wire on the sheething was a random burn mark it looked like. I know it was not touching the header at all when this happened.

Does anybody have any idea what is going on with this o2 sensor? Does it look like a short or soemthing? If you need better pics of anything et me know i will bring my camera to work tomorrow
Thanks a lot, Jeff

 

Was it the same wire both times and what was the color of the wire that burned?

 

Not sure wy that would happen. But check the engine sensor fuse in the fuse block under the hood. That probably blew when it shorted out the first time.

 

well.... i did my about 2 days ago and have no problems....have the same stuff you do and i just made sure i pulled the passanger side o2 sim down and way away from the header.....just make sure you have good clearance from all wires.....the ses light will come on right when you start it up but you have to drive it around for a while and it will go off if you have everything hooked up right.....the computer has to get use to it.....did you get the block off plates???????

 

I believe it was one of the brown wires that broke. I did not check the fuses, but i will tomorrow morning. The pics are auctually of the first sensor that blew but the second one did the same thing, on the same wires. Thanks for the replies... Oh yeah when we first started it up there was no SES light until we drove it for about 2 minutes then the computer registered the slow o2 readings and triggered the light.

 

What is the corresponding wire on the chassis harness that plugs into the wire that burned? I suspect it is the pink wire bringing voltage to the heater circuit. If that is the case, the only way to burn a wire like that is to be grounded at the point it burned.

But as mentioned before, it should have blown fuse 10 underhood.

 

Just as a follow up, the cause of it was a bad o2 extention. I figured out that they reversed all the wires on one of the connectors so it was causing a short. I switched them all around, and now everything works great!