Observing the sluggish performance of my a/f gauge, and seeing as how my sensor looks like it's been in there since 1984, I'm thinking I'll get a new one.

Is there any reason to spend $30 more to get a 4-wire than a 1-wire? If there is, is there any reason I can't buy a 3-wire and ground to the sensor body (either with a clamp or by soldering a wire to the sensor) and save myself 12 bucks?

 

The 1-wire is adequate, the 3-wire better for startup fuel-economy and deposit reduction, the 4-wire is the best for accuracy when trying to wire in an A/F meter. I have the 3-wire with the body clamped to batt neg, but sincerely believe that the 4-wire would provide a bit better signal. The ground-wire in the 4-wire goes directly to the sensor, not the body as does my clamp. Maybe very little difference, but the voltage output you are reading from that O2 sensor is a fairly small window (.2-.9 vdc). If I had to replace mine, I'd go with the 4-wire.

Be sure to run every ground to the batt neg, or a very suitable alternative (fuse/relay board ground maybe).

Good Luck!