P0442 on Your 2020 Nissan Murano: The Investigation
The P0442 code on your 2020 Nissan Murano indicates the engine control module has detected a small leak in the evaporative emission control system. This system captures fuel vapors from the gas tank and recycles them through the engine. A leak approximately the size of a 0.020-inch opening was found during the automated self-test.
The 2020 Murano is a midsize crossover powered by a 3.5L V6 engine paired with Nissan's Xtronic CVT transmission. After several years of service, EVAP components have accumulated enough use for wear-related failures. Nissan's EVAP architecture uses the PVCV, canister vent control valve, and dedicated leak detection pump.
Top Causes Ranked
- Worn Gas Cap Seal — After several years of regular use, the gas cap O-ring can crack, harden, or become permanently compressed. This is the most common and cheapest fix at $10–$20.
- PVCV (Purge Volume Control Valve) Degradation — The 3.5L V6's heat cycling gradually wears the PVCV's internal seals. When the valve no longer seals completely, vapor escapes during system testing.
- Canister Vent Control Valve Failure — Moisture and road debris exposure over years of driving cause the vent valve to stick or fail to seal during leak tests.
- Vapor Line Aging — Rubber vapor hoses lose flexibility over time and develop hairline cracks at connection points.
- Leak Detection Pump Wear — The Nissan-specific pump can develop internal seal issues affecting test accuracy.
Diagnostic Steps
- Replace the gas cap — New cap ($10–$20), clear the code, drive for several days.
- Smoke test — Professional smoke test ($80–$150) reveals exact leak location.
- Nissan CONSULT diagnosis — Active testing of PVCV, vent valve, and leak detection pump.
- Inspect visible hoses — Check for brittle, cracked rubber connections.
Costs and Warranty
Repair costs: gas cap $10–$20, PVCV $140–$280, vent valve $110–$250, leak detection pump $200–$400, vapor lines $80–$200. The federal emissions warranty covers EVAP components for 8 years or 80,000 miles — check with your Nissan dealer.