What this product is A pair (2PCS) of universal M18 x 1.5 O2 sensor spacer/adapter extensions. These adapters are designed for oxygen (O2) sensors and related exhaust sensors that use an M18 x 1.5 thread, and can be used with sensors that detect nitric oxide content in engine exhaust to help optimize exhaust performance. Key benefits — why you need it Reduces false check engine light triggers: the spacer creates a small offset between the sensor and the direct exhaust stream, which can help prevent false lean/rich readings that otherwise cause a CEL. Protects the sensor and downstream components: spacing the sensor slightly away from high-heat or turbulent exhaust flow can extend sensor life and reduce premature failures. Simple, non-invasive modification: provides a quick, reversible way to adapt sensor position without welding or replacing exhaust parts. Universal fit for M18 x 1.5 systems: fits common automotive O2 sensor threads for broad compatibility. Features and specifications Quantity: 2 pieces per set. Thread size: internal and external thread pitch M18 x 1.5. Function: spacer/adapter extension and filter-style mini catalytic conversion effect to help stabilize sensor readings and address check engine light issues. Compatibility: universal fit for sensors and bungs using M18 x 1.5 threads (O2 sensors and compatible nitric oxide/exhaust sensors). Practical applications / use scenarios Aftermarket header or exhaust modification: use the spacers when an O2 sensor reports abnormal readings after installing headers or modified piping to avoid false CELs without changing sensor or ECU settings. Diagnostic and temporary fixes: install the adapter during troubleshooting to determine whether a sensor’s placement is causing incorrect readings before replacing parts. Track or off-road vehicles: when exhaust routing or elevated exhaust temperatures cause unstable sensor signals, these spacers offer a fast way to reduce exposure and stabilize readings. Installation notes Thread pitch: confirm both sensor and exhaust bung use M18 x 1.5 before installing. Installation is straightforward — screw the adapter between the sensor and the bung. Torque to manufacturer recommendations for your sensor to ensure a proper seal. Reversible: can be removed at any time without modifying the exhaust system. What’s included 2 x M18 x 1.5 O2 sensor spacer/adapter extensions. This product offers a simple, reversible solution to improve sensor stability and reduce false check engine lights on vehicles using M18 x 1.5 oxygen or exhaust sensors.