HC Adsorption Catalyst Efficiency Below Threshold - Bank 2
The P2424 code means the vehicle's onboard diagnostic system has detected: HC Adsorption Catalyst Efficiency Below Threshold - Bank 2. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $200 - $1500 (parts and labor)
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Common Symptoms
- Check Engine Light illuminated
- Failed emissions test for hydrocarbons
- Mild fuel odor from exhaust
- Reduced catalytic converter efficiency on bank 2
- No significant drivability symptoms
Probable Causes (Ranked by Likelihood)
- Degraded HC adsorption catalyst on bank 2 Very High
- Rich fuel mixture contaminating bank 2 catalyst High
- Exhaust leak on bank 2 before the catalyst Moderate
- Oil consumption fouling the catalyst Moderate
Frequently Asked Questions
Can I drive with code P2424?
Short distances are fine. The vehicle will have elevated hydrocarbon emissions but is generally safe to drive.
What causes P2424?
A degraded catalyst on bank 2 is most common. Address any rich-running conditions first as they accelerate catalyst deterioration.
Is P2424 expensive to fix?
Costs range from $200 to $1500. European vehicle catalytic converters are expensive. Fix root causes like rich running or oil burning first.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Compare bank 1 and bank 2 catalyst efficiency readings
-
Check for rich-running conditions on bank 2 using fuel trim data
-
Inspect exhaust manifold and pipes on bank 2 for leaks
-
Check for oil consumption that could foul the catalyst
-
Evaluate O2 sensor readings upstream and downstream of the bank 2 catalyst
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- 2012-2020 BMW 5 Series
- 2013-2021 Audi A6
- 2014-2022 Mercedes-Benz E-Class
- 2011-2019 Volkswagen Touareg
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