DIY: GenII O2 Sensor Harness Extension


Apr 3, 2006
Reaction score
This is not really a deep DIY it's rather simple. For those of us that have a need to extend our front O2 Sensor Wires due to aftermarket headers, etc. there's a solution out there. Casper's Electronics sells a 24" O2 Sensor Extension harness. It's "almost" plug and play but doesn't require splicing of wires.

This is the extension (about $27 from Jeg's), Casper's Part Number 109034.

You must be registered for see images attach

I stated it's "almost" plug and play because a slight modification is required in order for this extension to mate with your O2 engine wire harness, namely the adapter. Below, is a shot of the drivers' side O2 harness plug that connects to the O2 front sensor. This plug has a stub on it that will prevent it from mating with the extension harness. The stub needs to be shaved down or removed.

You must be registered for see images attach

Once this stub is removed it's simply a matter of connecting it to the extension.

Consider this wire extension as an alternative to splicing.

- ViperTony