The Skunk2 O2 sensor wire harness extension is designed for the '06-'15 Civic Si. These extensions are great for installing an aftermarket header where the OEM O2 sensor wires are not long enough to reach the new bung location. Designed for the Skunk2 header and exhaust.
For '06-'11 Civic Si - For use with an aftermarket race header in which it is necessary to extend the Primary Oxygen sensor