O2 Simulator & P0420 Bypass Tool | Off-Road O2 Bypass

Diagnose O2 sensors & catalytic converter issues fast. Our off-road O2 simulator helps clear P0420 codes. Ideal for testing, tuning & off-road use.

• Eliminate False P0420 Codes

If you're dealing with annoying check engine lights for P0420 – Catalyst System Efficiency Below Threshold, this off-road O2 sensor simulator is your ideal diagnostic solution. It mimics a downstream O2 sensor signal, allowing you to test whether the issue lies in your catalytic converter or oxygen sensor.

• Simulate Downstream O2 Sensor Voltage

This tool outputs a stable waveform between ~100 mV and ~800 mV — similar to what your ECU expects from a working downstream O2 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.

• 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.