Fits: 96-04 Mustangs with the 4.6 or 5.0 Engines. Eliminates the Check Engine Light on Modified Exhaust Systems. Listing Includes Two O2 Sensor Bypass Harness for Both Sides. Premium Made OEM Delphi-Packard Connectors, Terminals and Seals. 257F (125C) Heat Resistant Nylon Delphi-Packard Certified Loom Tubing. Eliminates the Check Engine Light on Modified Exhaust Systems With Headers, X-Pipes, H-Pipes and High Flow Catalytic Converters for your 96-04 4.6 or 5.0 Mustang. Premium made harness with high temperature cross-linked polyethylene TXL wire, OEM connectors, pins and seals to ensure a secure proper fit. Designed to be used with after market exhaust systems that trigger your check engine light. The Oxygen Sensor Open Loop Harness will prevent the check engine light from coming on by simulating the proper Oxygen (O2) sensor signal to the computer. FOR OFF ROAD USE ONLY. Dual kit includes both the left and right sides. Note: In some cases the passenger side O2 Sensor Plug is different. In these instances the removal of the plastic locating tab will be required. NOTE: All o2 - OLP and Catalytic Converter Delete tuning products are STRICTLY FOR OFF-ROAD USE ONLY or use in countries outside of the United States that do not have emissions requirements! These products are NOT for use on any vehicle registered for highway use in the USA. According to the EPA Clean Air Act, they are illegal for use on any Federal, State, or Local public highways and illegal use is punishable by the penalties enacted by the mentioned laws.