What it means
The control module detects that the HC adsorption catalyst efficiency on bank 2 is below its calibrated threshold. The code does not by itself establish the cause or guarantee a particular exhaust odor.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The hydrocarbon (HC) adsorption catalyst on bank 2 stores and releases hydrocarbons to help control emissions, especially under conditions for which adsorption is used. The module evaluates related exhaust-sensor data and sets this code when bank 2 catalyst efficiency is below its calibrated threshold; it does not by itself prove the catalyst has failed.
Common causes
Most likely first.
- Degraded or damaged HC adsorption catalyst
- Fault in related exhaust sensing
Symptoms
- Check engine light on
- Possible failed emissions inspection
How to diagnose it
- Check freeze-frame data and other engine or emissions codes to see the conditions when bank 2 HC adsorption catalyst efficiency fell below threshold.
- Inspect the bank 2 exhaust and sensor wiring for leaks, damage, loose connectors, or heat-related faults that could affect the efficiency reading.
- Check live data from the sensors used to assess bank 2 catalyst operation and compare it with bank 1 if the engine has one.
- Verify that the bank 2 sensors and their circuits respond correctly using the manufacturer's specifications before judging catalyst performance.
- If sensor readings and exhaust integrity are sound, test the bank 2 HC adsorption catalyst using the manufacturer's diagnostic procedure.
Common fixes
- Repair an exhaust leak affecting the bank 2 catalyst or sensor readings.
- Repair damaged wiring or connectors for the bank 2 exhaust sensors.
- Replace a sensor only if testing confirms that it is reporting incorrectly.
- Replace the bank 2 HC adsorption catalyst if testing confirms its efficiency is below specification.
Can I keep driving?
If the engine runs normally, you can usually drive while arranging diagnosis, but emissions may be higher and the vehicle may fail an emissions inspection. Avoid ignoring additional misfire or overheating symptoms, which can damage exhaust catalysts.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.