Catalyst Heater Circuit Intermittent Bank 2

Common symptoms

What you'll notice

• Check and potentially replace the oxygen sensor in Bank 2
• Inspect and repair any wiring issues or loose connections related to the catalyst heater circuit
• Test and replace the catalyst or catalytic converter in Bank 2 if necessary
• Verify and fix any issues with the powertrain control module (PCM) or engine control unit (ECU)
• Perform a thorough inspection and potential repair of the exhaust system in Bank 2

Common causes

Most likely first

1. Faulty oxygen sensor
2. Malfunctioning catalytic converter
3. Damaged or deteriorating wiring or connectors
4. Faulty engine control module (ECM)
5. Exhaust leak

How to diagnose & fix

Work through it in order

1. Loss of engine power or sluggish acceleration
2. Engine misfires or stumbles
3. Reduced fuel efficiency
4. Check Engine Light illuminates
5. Strong smell of rotten eggs (sulfur) from the exhaust