OBD-II code · Powertrain (generic, extended)
P2424 HC Adsorption Catalyst Efficiency Below Threshold Bank 2
The hydrocarbon adsorption catalyst on bank 2 - which traps HC during cold-start until the main catalyst lights off - is degraded; HC slip during cold start is above the calibrated threshold.
Is it safe to drive with P2424?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyCatalyst adsorber aged
Symptoms
- Check engine light on
- Failed emissions inspection
- Possibly slightly increased fuel consumption
- Sulfur (rotten egg) smell from exhaust under load
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1.5–5 h
- Emissions test
- Likely to fail
- Parts involved
- Hc Adsorption Catalyst B2
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.