Diagnose O2 sensors & catalytic converter issues fast. Our off-road O2 simulator helps diagnose P0420 codes. Ideal for testing, tuning & off-road use. Eliminate False P0420 Codes during testing Simulate Downstream or Upstream O2 Sensor Voltage This Downstream tool outputs a stable waveform between ~100 mV and ~800 mV — similar to what is expected from a working downstream sensor. Use it to confirm sensor performance or identify faulty converters. This Upstream tool outputs an osculating waveform between 100 mV and 800 mV similar to that of what would be expected for the upstream sensor. Use it to confirm sensor performance or identify faulty converters. Built for Off-Road Diagnostics & Tuning This product is designed strictly for off-road, racing, and testing purposes. It should never be used to tamper with or bypass emissions systems on public roads. Compatible with Most 1-4 Wire O2 Systems Designed to work with 1 to 4-wire O2 sensor setups, this device is compact and easy to install. Connect power, ground, and signal — you're ready to start diagnosing. Narrowband Sensors: Typically have 1 to 4 wires. Wideband Sensors: Usually feature 5 or more wires, including additional circuits for the oxygen pump and reference signals. Not for On-Road Emissions Use ⚠️ This simulator is not intended for use on public highways or roads. It is for diagnostic and off-road testing only. Always comply with your local emissions laws and regulations.
