P0442 on 2018-2021 Nissan KICKS: EVAP Small Leak Causes and Fixes

What's Unique About the 2018-2021 Nissan KICKS

For the Nissan KICKS and other modern Nissans, the P0442 code is so frequently caused by a simple gas cap issue that Nissan has issued multiple Technical Service Bulletins (TSBs) guiding technicians to check it first. These vehicles have a dedicated "LOOSE FUEL CAP" warning light to alert the driver even before a Check Engine Light appears. If the cap isn't the problem, the EVAP canister vent control valve is a very common failure point across the Nissan lineup, including the KICKS and its platform-mate, the Nissan Versa.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light is illuminated
• A faint smell of fuel, especially around the rear of the vehicle
• "LOOSE FUEL CAP" warning on the dashboard, even after tightening the cap
• Difficulty starting the engine or a rough idle immediately after refueling (points strongly to a failing vent control valve)

Most Likely Causes

1. Loose or Faulty Gas Cap 🔴 High Probability → Shop Fuel Tank Cap This is the most common cause across all modern Nissan vehicles, as highlighted in multiple TSBs (NTB13-097J). The rubber O-ring on the cap can wear out, crack, or become dirty, preventing a proper seal. Using non-OEM caps is a frequent source of this code as they may not seal to factory specifications.
   How to confirm: Remove the gas cap. Inspect the rubber O-ring for any visible cracks, stiffness, or damage. Clean the sealing surface on the filler neck. Reinstall the cap, ensuring it clicks several times. Clear the code and drive for a few days to see if it returns.
   Typical fix: Replace the gas cap with a new, genuine OEM part (Nissan P/N: 17251-5RL0B). Aftermarket caps are not recommended as they are a known cause of persistent EVAP codes.
   Est. part cost: $45-$60
2. Faulty EVAP Canister Vent Control Valve 🟡 Medium Probability → Shop Vapor Canister Vent Valve This valve, located near the EVAP canister at the rear of the vehicle, is a common failure point on many Nissan models. It can get stuck open or closed due to dirt, debris, or internal failure, creating a leak path that the system detects. A key symptom of its failure is difficulty starting after filling the gas tank.
   How to confirm: The valve can be tested with a scan tool that allows for bidirectional control. A technician can command the valve closed and perform a smoke test to see if smoke escapes from the valve. A DIY method involves removing the valve and attempting to blow through it; it should be open by default when unpowered. A clicking sound can often be heard when it's activated with a scan tool.
   Typical fix: Replacement of the EVAP canister vent control valve. It is typically mounted to or near the charcoal canister at the rear of the vehicle.
   Est. part cost: $60-$90
3. Cracked or Disconnected EVAP Hoses ⚪ Low Probability Rubber hoses can become brittle and crack over time due to heat and age. A small crack in any of the vapor lines connecting the fuel tank, charcoal canister, and purge valve can trigger a P0442.
   How to confirm: A visual inspection may reveal obvious cracks, especially at connection points. However, a definitive diagnosis usually requires a smoke test, where a machine fills the EVAP system with a visible vapor to pinpoint the exact location of the leak. 🎬 Watch: A pro guide on performing your own smoke test.
   Typical fix: Replace the specific section of cracked hose. Small repairs can be made with new hose and clamps.
   Est. part cost: $10-$30
4. Faulty EVAP Canister Purge Valve ⚪ Low Probability → Shop Vapor Canister This valve is located in the engine bay and controls the flow of fuel vapors from the canister to the engine. While it can fail, it's less common for it to cause a small leak code than the vent valve. It's more likely to cause other performance issues or different codes if it fails.
   How to confirm: With the engine off, disconnect the hose from the valve that leads to the intake manifold and see if vacuum can be pulled. The valve should be normally closed. A scan tool can also be used to command it open and closed to check for proper function.
   Typical fix: Replace the purge valve. This is a relatively simple replacement located in the engine bay. 🎬 See this walkthrough on testing and replacing the purge valve.
   Est. part cost: $50-$150

Rare But Worth Checking

• Cracked Charcoal Canister: → Shop Vapor Canister The plastic housing of the canister itself can develop a hairline crack from road debris impact or age, creating a small leak. This is usually found only with a smoke test and is a more expensive repair.
• Corroded Fuel Filler Neck: → Shop Fuel Filler Neck Rust or corrosion on the lip of the fuel filler neck where the gas cap seals can prevent a proper seal, even with a new cap. Cleaning the surface with a wire brush may help, but severe corrosion may require filler neck replacement.

Diagnosis Steps

1. Check for a "LOOSE FUEL CAP" message on the dash.
2. Inspect the gas cap: Remove it, check the seal for cracks or damage, and clean the filler neck surface.
3. Reinstall the gas cap, ensuring it clicks multiple times. Clear the P0442 code with a scanner.
4. Drive the vehicle over several separate trips. Per Nissan TSB NTB13-097J, the EVAP self-test runs under specific conditions, not on every drive, so it may take a few days for the light to either stay off or return. Do not rely on a single short test drive for confirmation.
5. If the code returns, replace the gas cap with a genuine OEM part (P/N: 17251-5RL0B). Clear the code and drive again.
6. If the code persists, perform a visual inspection of all accessible EVAP hoses in the engine bay and under the vehicle for obvious cracks or disconnections.
7. If no visual faults are found, the next step is a professional smoke test to find the source of the leak. This is the definitive method for finding cracks in hoses, the canister, or leaking valves.
8. Based on the smoke test results, replace the faulty component, which is commonly the EVAP canister vent control valve (P/N: 14935-JF02C).

Parts You'll Likely Need

• Fuel Filler Cap (OEM #17251-5RL0B) — This is the most frequent cause of P0442 on modern Nissans due to a worn or damaged seal. OEM is strongly recommended.
  Trusted brands: Nissan Genuine OEM
  OEM price range: $45-$60
  Aftermarket price range: $10-$25
• EVAP Canister Vent Control Valve (OEM #14935-JF02C) — A very common failure point on Nissan vehicles that causes various EVAP codes, including P0442. It can get stuck or fail to seal.
  Trusted brands: Nissan Genuine OEM, Dorman
  OEM price range: $60-$90
  Aftermarket price range: $40-$70
• EVAP Canister Purge Valve (OEM #14930-3YM0A) — Less common than the vent valve for this specific code, but still a possible cause if it gets stuck partially open. Located in the engine bay.
  Trusted brands: Nissan Genuine OEM, Hitachi
  OEM price range: $120-$160
  Aftermarket price range: $50-$90

Related Codes That Often Appear With This One

• P0455 — Indicates a large EVAP leak. A component failure might start as a small leak (P0442) and worsen over time, triggering a large leak code. Both are often addressed with the same diagnostic steps.
• P0456 — Indicates a very small EVAP leak. This code is closely related to P0442 and points to the same set of potential failures, just at a different leak-size threshold. Nissan groups P0442, P0455, and P0456 together 🎬 Watch: How to quickly solve these common Nissan EVAP codes. in its service bulletins.

Technical Service Bulletins (TSBs) & Recalls

• NTB13-097J: 'EVAP LEAK DTC P0442, P0455, P0456 INFORMATION' - This bulletin provides the standard diagnostic procedure for these common EVAP codes. It emphasizes checking the fuel cap first and explicitly states that a test drive is not a valid way to confirm a repair, as the EVAP self-test runs on its own schedule.
• NTB13-097g: 'ALL MODEL YEAR 2012 AND NEWER NISSAN VEHICLES; EVAP LEAK DTC P0442, P0455, P0456 INFORMATION' - An earlier version of the same bulletin with similar guidance, confirming this has been a long-standing diagnostic procedure for Nissan.

Mechanic-Grade Diagnostic Values

• EVAP Canister Vent Control Valve Solenoid Resistance — expected: 48 - 65 Ohms. Failure: A reading of 0 Ohms (short circuit) or infinite/OL (open circuit) indicates a failed coil.
• EVAP Canister Purge Valve Solenoid Resistance — expected: 30 - 38 Ohms. Failure: A reading significantly outside this range, or 0/OL, indicates a faulty solenoid coil.
• Fuel Tank Pressure (FTP) Sensor Voltage (Key On, Engine Off) — expected: ~1.5V - 2.5V (varies by atmospheric pressure). Failure: Voltage is stuck high (near 5V) or low (near 0V) and does not change when the gas cap is removed.

Scan Tool Commands That Help

• Nissan CONSULT or advanced bidirectional scan tool: EVAP System Leak Test — Used to command the EVAP system to seal (by closing the vent valve) and monitor the fuel tank pressure sensor to confirm if a leak is present without needing a smoke machine for initial verification.
• Nissan CONSULT or advanced bidirectional scan tool: Vent Valve Control — Allows a technician to manually command the vent valve to open and close. Listening for an audible click can confirm the solenoid is activating. When commanded closed, a smoke test can then verify if the valve is sealing properly or leaking.

Wiring & Ground Locations

• EVAP Vent Control Valve Connector — At the EVAP vent control valve, which is mounted on or near the charcoal canister at the rear of the vehicle, near the fuel tank.. This connector provides power and the ECM ground signal to close the valve for the leak test. Corrosion or a bad connection here can prevent the valve from closing, causing the system to fail its self-test and log a P0442. One pin should have 12V with the key on, and the other is the ground controlled by the ECM.
• Fuel Tank Pressure (FTP) Sensor Connector — Typically mounted on the fuel tank or on the EVAP canister assembly.. This is a 3-wire connector that provides the ECM with the pressure reading inside the tank. A bad connection can send an erroneous signal, making the ECM believe there is a leak when there isn't one. It carries a 5V reference, a ground, and the signal wire.

OEM Part Supersession History

• 14935-JF00A, 14935-JF00B, 14935-JF00C, 14935-JF00D, 14935-JF00E, 14935-JF01B, 14935-JF01C → 14935-JF02C — Standard part revision and improvement by the manufacturer over time.
  Heads up: The latest part number, 14935-JF02C, is the correct replacement for all previous versions and is widely used across many Nissan models.
• 17251-3JA0C, 17251-5RL0A → 17251-5RL0B — Updated design for better sealing or material durability.
  Heads up: 17251-5RL0B is the current recommended OEM replacement for the 2018-2021 Kicks.