Air/fuel guage for 99 Z24

I searched through the site pretty thoroughly and I didn't find this one.
I have a 1999 Cavalier Z24 and had bought an air/fuel ratio gauge and I have the accessory (+) and ground wires installed but I have yet to find where to conn the purple wire to. I know it needs to go to the pre-converter sensor but I can't find the sensor or the wire coming from the ECU. If any one has a 1999 Z24 and has one of these guages and has pictures of their install or can give some good directions on where they connected theres it would be much appreciated. :banghead:

1) stand to passenger side of engine.
2) Looks towards rear side of engine towards firewall
3) Note there is a header there.
4) Locate the only abnormal extremedy protruding off the header where the pipe converge into 1 and will have 1 wire comming off that.
5) Trace this back to a black connector with an orange safty clip.
6) See wire on opposite side and note its purple.

Splice and solder on that puppy and your good to go buddy. I'd show you pics of mine, but i have the 2.2 and its a little different location.

Thanks Irocjunkie. I think I have been missing it because there is a heat sheild over the manifold. Which if I looked in the Haynes manual for the exhaust manifold I would have seen. Thanks again.

would anyone know where that sensor is on my 90 cav 2.2. Im having the same issue. Any help would be great.

Oh, and where would I hook up the sensor for my volt meter:lol: