i have a 94z and i just got a a/f ratio gauge the directions say to hook up 1 wire to the signal wire from the o2 sensor btwn the pcm and the o2 connector but where would i find this wire and i have 2 o2 sensors 1 in each manifold should i just weld in a new sensor on the y pipe to get the best reading ne help would b great

 

Easiest would be to connect to the wire at C8 or C20 (that is the clear connector on the PCM, either cavity 8 or 20) Wire color will be purple for C8 and purple/white for C20. If you use one of those then you can easily run it into the interior through a relatively large rubber grommet that is right behind the PCM.

Alternatively, you can find these same wires at the connector for each O2. Just make sure you connect to the harness side, not the O2 side of that connector.

Note: this type of A/F reading will NOT be accurate. It will be accurate at or near 14.7 to 1 (Stoich) but can not be relied on for WOT tuning. Only a wide-band setup will work for that.

Todd