The O2 sensor wire harness extension is designed for 2006-2014 Civic Sis. These extensions are great for installing an aftermarket header where the oem O2 sensor wires arent 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

Alpha Series Race O2 Sensor Extension; Plug And Play; For Use w/Skunk2 Headers And Exhaust;

Skunk2 06-11 Honda Civic Si O2 Extension

Alpha Series Race O2 Sensor Extension

06-15 Civic Si O2 Ex