63 Right Bank O2 Sensor Circuit Open

How to read it

Code 63 reads as 6 flashes, pause, 3 flashes on the check-engine light. Jump terminals A and B on the ALDL connector with the key off, then turn the key on with the engine off and count the check-engine flashes.

What does GM code 63 mean?

63. Right Bank O2 Sensor Circuit Open. This code sets when your vehicle computer detects right bank o2 sensor circuit open.

Common causes of 63

• Failed right bank O2 sensor
• Open sensor signal wire
• Corroded O2 connector
• Exhaust leak near the sensor

How to fix 63

1. Read codes with a paperclip jumper and confirm code 63 repeats
2. Inspect the sensor wiring for burns on the exhaust
3. Check the connector for corrosion and loose pins
4. Watch sensor voltage on a scan tool and look for switching
5. Fix exhaust leaks ahead of the sensor
6. Replace the sensor only after wiring tests clean