Fault code P1442 – a step-by-step guide to diagnosing and fixing it

Error code P1442 is displayed and the check engine light is on - what does this mean?

The DTC P1442 is a manufacturer-specific trouble code that is recognized by OBD-II/EOBD diagnostics and indicates a problem in the evaporative emission control system (EVAP). This trouble code typically refers to a fault in the vent valve or vent line of the EVAP system. Different manufacturers may vary on the exact definition, with Toyota, Lexus and some other brands using this code for EVAP system faults.

What can cause this fault code?

• Defective EVAP vent valve (canister vent valve)
• Clogged or damaged vent line
• Faulty electrical connections to the vent valve
• Defective activated charcoal canister (Charcoal Canister)
• Loose or corroded plug connections
• Damaged vacuum hose system
• Faulty engine control unit (ECU/PCM)
• Clogged air filter in the EVAP system

What symptoms occur in parallel with fault code P1442?

• Check engine light: The check engine light is permanently illuminated
• Fuel smell: Smell of gasoline, especially when refueling or parking
• Starting problems: Difficult starting after refueling
• Power loss: Slight reduction in engine power
• Increased fuel consumption: Measurably higher fuel consumption
• Fuel tank problems: Difficulty refueling or premature shutdown of the fuel nozzle
• Idle irregularities: Uneven engine running at idle

How can the problem with error code P1442 be rectified?

• Repairing the EVAP system requires a systematic diagnosis to identify the exact cause.
• Replace the EVAP canister vent valve: Replace the defective Canister Vent Valve with a new original part and check electrical connections
• Replace vacuum hoses: Check all EVAP vacuum hoses for cracks or blockages and completely replace damaged lines
• Replace the charcoal canister: Replace the Charcoal Canister with a new one if clogged or damaged and clean connections
• Repair electrical connections: Clean plug connections to the vent valve, check contacts and replace defective cables
• Complete EVAP system diagnostics: Have a professional smoke test carried out to locate leaks in the entire evaporation system
• Reset the engine control unit: After repair, clear fault code and perform a test drive to verify repair