The Kooks O2 extension kit for 2015+ Dodge Hellcat (and 2018+ Trackhawk) provides 2 front 6" 8-pin extension harnesses and 2 rear 18" 4-pin extension harnesses as replacements for damaged or missing extensions. These harnesses match the items included with Kooks header kits where required, restoring proper oxygen sensor routing during header or exhaust installation and maintaining OE-style fit.
Kooks 2015+ Dodge Hellcat 02 Sensor Wiring Extensions