I have a 1987 trans am gta, with a 305 / 5 speed. I recently did a header swap. And for the life of me I can't find the wire that goes to the driver side 02 sensor. I only have a driver side 02 sensor from stock, although there was an 02 sensor wire on the passenger side, but it's definitely not long enough to reach the factory driver side 02 sensor. Anyone tell me exactly where the driver side 02 sensor comeso out of the firewall at? Wire color?

 

The wires on the passenger side are knock sensor (white, near oil pan rail) and secondary fan switch (black, sensor in head).

The O2 wire is purple, and should be coming from a harness bundle close by.

At least that is what I can remember.

 

So the purple wire comes out of the pass side? The wire from the pass side that has an 02 sensor plug is a green wire. I tried using a butt connector and running it to the driver side 02 plug. But my car is still dieing after I put it under load and I'm almost positipositive it's the 02 sensor not being connected.

 

The O2 sensor connector should exit from the wire harness bundle under the power brake booster. The harness bundle runs along the bottom of the driver's side fender inside the engine compartment.

 

The purple wire from the passenger side should be your knock sensor. There is also a green wire on the passenger side, but that is for the Coolant Fan switch. The wire for the O2 should have a connector on it from the engine harness (under the brake booster) since all 02 sensors have the proper connector on their pigtail.