P2440

The P2440 code means the PCM has detected that the secondary air injection system switching valve for Bank 1 is stuck in the open position. This valve controls when fresh air is routed into the exhaust manifold. It should only be open during cold starts to help the catalytic converter warm up quickly. When it is stuck open, air continues flowing into the exhaust beyond when it should, affecting the air-fuel mixture and oxygen sensor readings.

A stuck-open switching valve can cause a hissing or whistling noise from the engine area and may create a lean running condition because extra air is entering the exhaust. The oxygen sensors may read incorrectly, potentially causing the PCM to adjust the fuel mixture improperly. You may also notice a rough idle and the engine running poorly when cold.

This code is particularly common on Toyota and Lexus V6 and V8 engines. The switching valve is typically located on or near the exhaust manifold and can be difficult to access. Replacement parts range from $150–$350, and dealer parts can be significantly more expensive. On Toyota/Lexus vehicles, aftermarket bypass kits are available for around $400–$500 that eliminate the secondary air system entirely, though this may not be legal in all states for emissions-tested vehicles.

Severity

Symptoms

• •Check Engine Light is on
• •Hissing or whistling noise from engine area
• •Rough idle especially when cold
• •Lean running condition at idle
• •Failed emissions test
• •Possible exhaust smell in engine bay

Likely Causes

Estimated Cost

Common Fixes

1. Replace secondary air injection switching valve
2. Replace air switching valve solenoid
3. Clean carbon deposits from valve and passages
4. Repair or replace vacuum lines
5. Repair wiring short circuit

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