P0442 Mitsubishi Code - EVAP System Small Leak Detected
Quick Answer
The Engine Control Module (ECM) tests the Evaporative Emission (EVAP) system for the following conditions: - Large and small leaks - Excess vacuum - Purge flow during non-commanded conditions - Fuel Level and Fuel Pressure sensor faults - EVAP Purge and Vent Valve faults The ECM monitors the Fuel Tank Pressure sensor in order to determine the level of vacuum/pressure in the EVAP system. Common causes include Missing or loose fuel cap, Incorrect fuel filler cap used, Fuel filler cap remains open or fails to close. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
- What it means
- P0442 Mitsubishi indicates EVAP System Small Leak Detected.
- Common causes
- Common causes include Missing or loose fuel cap, Incorrect fuel filler cap used, Fuel filler cap remains open or fails to close.
- Severity
- Low - monitor the vehicle and repair when practical.
- Can I drive?
- The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
Code P0442 Mitsubishi Description
- Large and small leaks
- Excess vacuum
- Purge flow during non-commanded conditions
- Fuel Level and Fuel Pressure sensor faults
- EVAP Purge and Vent Valve faults
The ECM monitors the Fuel Tank Pressure sensor in order to determine the level of vacuum/pressure in the EVAP system. The ECM commands both the EVAP Purge Solenoid and the EVAP Vent Valve ON when the conditions are met in order to apply an engine vacuum to the EVAP system. The ECM commands the EVAP Purge Solenoid OFF once the system has reached a predetermined level of vacuum. This test verifies if a vacuum can be achieved in the EVAP system. Failure to develop a vacuum may be caused by a large leak or a restriction.
What are the Possible Causes of the DTC P0442 Mitsubishi?
- Missing or loose fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- EVAP canister or fuel tank leaks
- EVAP system hose leaking
- Fuel tank leaking
How to Fix the DTC P0442 Mitsubishi?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0442 Mitsubishi code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P0442 Mitsubishi Code
1. What does the OBDII code P0442 for Mitsubishi mean?
The code P0442 indicates that the EVAP system has detected a small leak in the system, specifically in the evaporative emission control system.
2. What are the common symptoms of a P0442 code in a Mitsubishi?
Common symptoms of a P0442 code include the check engine light coming on, a slight decrease in fuel efficiency, and potentially a noticeable gasoline odor around the vehicle.
3. What are some possible causes of the P0442 code in a Mitsubishi?
Possible causes of a P0442 code include a loose or damaged gas cap, a cracked or damaged EVAP system hose, a faulty EVAP canister purge valve, or a leak in the EVAP system.
4. How serious is a P0442 code in a Mitsubishi?
While a P0442 code is not an emergency situation, it should not be ignored. Ignoring the code could lead to increased emissions, reduced fuel efficiency, and potential damage to the vehicle's emission control system.
5. How can I diagnose a P0442 code in my Mitsubishi?
Diagnosing a P0442 code typically involves inspecting the gas cap for tightness, visually checking the EVAP system components for damage or leaks, and using a smoke machine to pinpoint the exact location of the leak.
6. Can I repair a P0442 code in my Mitsubishi myself?
Depending on the cause of the P0442 code, some repairs can be done by a DIY enthusiast. Replacing a faulty gas cap or a damaged EVAP system hose may be manageable, but more complex issues may require professional assistance.
7. How much does it cost to repair a P0442 code in a Mitsubishi?
The cost of repairing a P0442 code can vary widely depending on the specific cause of the issue. Simple fixes like replacing a gas cap may cost under $50, while more complex repairs involving the EVAP system components could range from $100 to $500 or more.
8. Will a P0442 code in my Mitsubishi affect its performance?
In most cases, a P0442 code will not have a significant impact on the performance of the vehicle. However, ignoring the code could potentially lead to more serious issues over time, so it's best to address the problem promptly.
9. Can a P0442 code in a Mitsubishi clear on its own?
In some cases, a P0442 code may clear on its own after a few driving cycles if the issue was minor or temporary. However, if the problem persists, it's recommended to diagnose and repair the underlying cause to prevent further issues.
10. How can I prevent a P0442 code from recurring in my Mitsubishi?
To prevent a P0442 code from recurring, make sure to tighten the gas cap properly after refueling, avoid overfilling the fuel tank, and regularly inspect the EVAP system components for any signs of damage or wear.
Discuss the causes and fixes for P0442 Mitsubishi OBDII Code
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Saludos , tengo mitsubishi outlander asx sport 2011 con código p0442 pequeña fuga detectada del EVAP para saber posibles causas , pero de casualidad le apago la luz del service soon le lleno el tanque de gasolina y me prende la luz de service soon cuando llega a medio tanque que podría ser o si alguien le a pasado lo mismo.
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Podria se la tapadera del tanque de gasolina. Le recomiendo que comience con eso.
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Hi all!,
I just got my engine light on, and when checking the code i got this P0442 code. The interesting thing is that it came on right after i accelerated rather forcefully to join a highway. I checked the gas cap, but it is tightly closed so it does not seem to be the reason(unless the gasket is broken and is not working as expected). I dont perceive any gasoline odor. Any ideas what i should be checking ? -
Unfortunately there are many things that could set the P0442 code. Let me check what are the most common problems for your vehicle. What is the model and year of your vehicle?
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Lancer ES 2005. a bit old, but have been running without problems since i got it. Just lately the engine check has turn on twice.. first time it was the Oxy sensor (replaced and worked fine), and now this.
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According to a national database of repairs, here are the most likely cause for the P0442 code for your model year.
Gas Cap - 84 times the Gas Cap was the problem
Fuel Tank - 14
Evap Canister Vent Solenoid - 9
Evap Line - 5
Powertrain Control Module - 5
Fuel Filler Neck - 4
Evap Canister Filter - 3Since there are too many thing that can set the P0442 code, I recommend starting with the gas cap. Usually is the gas cap seal that fails and let the gas escape.
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Thanks!.. i will double check on the gas cap. I hope i am lucky enough to be on the top reason the problem shows up.
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Yuuup, it was the gas cap. I just replaced it and drove ~100 miles after resetting the engine light, and it never came on. Thanks!
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- Replaced gas tank fuel cab with brand new.
- Replaced purge valve with brand new.
Now, the code 0456 was gone and after a week. the Code 0442 came out. what will be next to do?
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Thanks for the detailed info. You’re definitely heading in the right direction—P0456 and P0442 are both EVAP small leak codes, and sometimes fixing one just exposes the next weakest point.
Here’s what I’d check next:
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EVAP vent valve (canister side) – If it’s sticking open or not sealing fully, it can trigger a small leak code like P0442. Even if the purge valve is new, the vent side needs to seal during the self-test.
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Charcoal canister and hoses – Check for any cracked or loose hoses between the tank, canister, and valves. Over time, heat and age cause small cracks that are hard to see but leak under pressure.
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Smoke test – This is the fastest way to find small EVAP leaks. A shop can pressurize the system with harmless smoke and look for leaks around the filler neck, top of the tank, or connections.
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Fuel tank pressure sensor – Rare, but if it gives bad readings, it can trigger small leak codes even if the system is sealed. Only check this if everything else looks solid.
Since P0442 is a small leak, it's usually something minor like a cracked hose, vent valve issue, or loose connection. If you can’t spot anything obvious, I’d recommend a smoke test before replacing more parts.
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