P2424: HC Adsorption Catalyst Efficiency Below Threshold Bank 2
What to do
The car drives normally and will fail an emissions test. If only one bank is reporting, be sceptical of age as the explanation — both sides have done the same mileage, so a fault on one usually means something local to that side, such as an exhaust leak or a drifting sensor. Have those ruled out before an expensive exhaust component is replaced.
What this code means
The hydrocarbon adsorption catalyst on the second bank is not storing and releasing as expected. The mechanism and the caution about oxygen sensors are at P2423.
One bank alone is worth noting, because these devices age with heat and use and both banks see broadly the same conditions. A single-bank failure therefore often means something local rather than age — an exhaust leak on that side, a sensor drifting, or a history of oil consumption on that bank — and those are cheaper to establish than the part is to replace.
Likely causes
Start here
- Faulty oxygen sensor · moderate
- Exhaust leak before the sensor · moderate
- Degraded hydrocarbon adsorber substrate · specialist
Less common
- Excessive oil or coolant consumption · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about P2424.