These O2 sensor eliminator kits are used when you want your bike to run without O2 sensors, for example when you want to change air/fuel ratio at idle and part throttle for racing applications using Diag4Bike, Daytona Twin Tec Twin Tuners in conjunction with a Daytona Twin Scan Tool, Dynojet Power Commander, Screamin' Eagle Pro Super Tuner and similar. The eliminators plug into the stock wiring harness and simulate a cold sensor condition, causing the ECM to remain in "open-loop" operation. Eliminators for 4-wire heated sensors can also be used to eliminate the secondary O2 sensors on Euro-5 motorcycles but then their only function is to keep moisture and dirt out of the wiring side connectors to keep them intact for later use. Related CEL (Check Engine Light) and DTC's (Digital Trouble Codes) can be disabled with Diag4Bike software and a Diag4Bike Tuning License.