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P0442 Evap Emission Control Small Leak Detected

Technical Description

Evaporative Emission Control System Leak Detected (small leak)

What does that mean?

This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. Although generic, the specific repair steps may vary depending on make/model.

The vehicle's PCM (powertrain control module) tests the evaporative emissions (EVAP) system for large and small leaks among other conditions. In the case of this DTC, it indicates a fuel vapor leak in the EVAP control system. It means a very small leak has been detected. In fact, the leak can be from a hole as small as 0.04" in diameter. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system.

Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.

Symptoms

The only thing you will notice is the Malfunction Indicator Lamp (MIL) a.k.a. Check Engine Light will be illuminated. You likely won't notice any drivability problems although sometimes a fuel odor may be noticed.

Causes

A code P0442 most likely means one or more of the following has happened:

Possible Solutions

With a P0442, the most common repair is to:

More advanced troubleshooting steps include:

Generally there are vehicle and model specific procedures for proper diagnosis of this DTC.

Sources: About.com

Other EVAP DTCs: P0440 - P0441 -P0443 - P0444 - P0445 - P0446 - P0447 - P0448 - P0449 - P0452 - P0453 - P0455 - P0456

Related P0442 DTC Discussions

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