Amazon.com: Bafx Products – For Android Only – Wireless …

If you have a P0420 code, you can monitor the oxygen sensor data to see if your catalytic converters are bad. Use it to diagnose a P0430 for a bad o2 sensor heater. This tool will pay for itself 4 times over the first time you use it to do a repair yourself over paying a shop or dealership. It’s invaluable to the DIY mechanic like myself.

https://www.amazon.com/BAFX-Products-Wireless-Bluetooth-Diagnostic/dp/B005NLQAHS