HomeTrouble CodesP2424

P2424 — Hc Adsorption Catalyst Efficiency Below Threshold Bank 2

Manufacturer-specificPowertrain (engine & transmission)

The P2424 code indicates that the hydrocarbon (HC) adsorption catalyst on Bank 2 is operating below a minimum efficiency threshold. This component is designed to trap hydrocarbons during cold-start conditions to reduce emissions before the primary catalytic converter reaches operating temperature.

Symptoms

What causes it — most likely first

1. Degraded HC Adsorption Catalyst

The catalyst material has physically deteriorated or become contaminated, losing its ability to adsorb hydrocarbons.

2. Exhaust Leak

A leak in the exhaust manifold or piping near the catalyst allows outside air to enter, skewing sensor readings.

3. Faulty Downstream Oxygen Sensor

A malfunctioning sensor on Bank 2 may report incorrect hydrocarbon levels, triggering a false efficiency code.

4. Engine Misfire

Unburned fuel from a misfire can overload the catalyst, leading to premature failure or temporary efficiency drops.

5. PCM/ECM Software or Hardware Fault

An error in the engine control module's processing of sensor data, though this is statistically rare.

How it's diagnosed

  1. Perform a visual inspection of the exhaust system for leaks or physical damage on Bank 2.
  2. Use a scan tool to check for accompanying misfire codes or fuel trim irregularities.
  3. Analyze freeze frame data to determine the exact conditions (temperature and load) when the fault occurred.
  4. Test the Bank 2 downstream oxygen sensor for proper response and voltage range.
  5. Perform a catalyst efficiency test by comparing upstream and downstream sensor data during a warm-up cycle.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationManufacturer-specific (P1/B1/C1/U1)

Frequently asked

Will replacing the PCM fix this code?

It is highly unlikely. P2424 is almost always caused by a physical failure of the catalyst, a sensor error, or an exhaust leak; replacing the PCM is rarely the correct solution.

Can the car still be driven with this code?

Yes, the vehicle is typically drivable, but it will fail emissions tests and may produce higher pollutant levels during cold starts.

Does this mean my main catalytic converter is bad?

Not necessarily. This code specifically refers to the HC adsorption catalyst, which is a separate function or component used for cold-start emissions management.