P0440 Nissan Code - EVAP Control System Small Leak
Quick Answer
The P0440 code for Nissan vehicles indicates a problem with the EVAP (Evaporative Emission Control) system, specifically a small leak. Common causes include Loose or damaged fuel cap, Cracked or deteriorated hoses in the EVAP system, Faulty purge valve. 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
- P0440 Nissan indicates EVAP Control System Small Leak.
- Common causes
- Common causes include Loose or damaged fuel cap, Cracked or deteriorated hoses in the EVAP system, Faulty purge valve.
- 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.
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Code P0440 Nissan Description
The P0440 code for Nissan vehicles indicates a problem with the EVAP (Evaporative Emission Control) system, specifically a small leak. The EVAP system is responsible for capturing and storing fuel vapors from the fuel tank, preventing them from escaping into the atmosphere. A small leak in this system can lead to increased emissions and potential fuel economy issues.
Common Causes of P0440 Nissan
- Loose or damaged fuel cap
- Cracked or deteriorated hoses in the EVAP system
- Faulty purge valve
- Leaking charcoal canister
- Damaged fuel tank
Symptoms of P0440 Nissan
- Check Engine Light illuminated on the dashboard
- Strong fuel odor around the vehicle
- Decreased fuel efficiency
- Engine misfires or rough idling
- Failed emissions test
How to Fix P0440 Nissan
- Check the gas cap: Ensure the gas cap is tightened properly or replace it if damaged.
- Inspect EVAP system hoses: Check for cracks or leaks in the hoses and replace any damaged ones.
- Test the purge valve: Test the purge valve for proper operation and replace if necessary.
- Check the charcoal canister: Inspect the charcoal canister for leaks or damage and replace if needed.
- Check the fuel tank: Inspect the fuel tank for leaks or damage and repair or replace as required.
Cost to Fix P0440 Nissan
The cost of repairing a P0440 code on a Nissan vehicle can vary depending on the specific cause of the issue and the labor rates of the auto repair shop. On average, the repair costs for this issue can range from $100 to $500, including parts and labor. However, it is important to note that diagnostic time and labor rates can vary based on factors such as location, vehicle make and model, and engine type. It is recommended to check with local auto repair shops for a more accurate estimate.
Tech Notes for P0440 Nissan
There is a Nissan Service Bulletin to help diagnose the P0440 code:
Nissan Factory Service Bulletin OBDII Code P0440
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Frequently Asked Questions about P0440 Nissan Code
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Discuss the causes and fixes for P0440 Nissan OBDII Code
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i have this code on a 1999 nissan altima gxe. p0440. where should i start. i did the gas cap thing by un srewing it and replacing it. but iam also getting codes p0325,p0440,p1490,p1448. and dont know where to start.. thanks
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You could start by erasing all the codes and work with the one that comes back first. You should also check the canister and make sure is not damage.
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I replaced gas cap it also had tune up v.alve cover gasket was fixed. check engine light is on. running out of money to keep getting it worked on. also have to fix ac and blower motor again. om sick and have to have ac.
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Unfortunately there are many things that could cause that code. The gas cap is the fisrt thing, but you already did that. If the code came up after the valve cover repair, then there is a chance that whomever did the valve covers left a loose hose or component.
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I have a P0440 code evap leak and a P0325 knock sensor code should i replace the purge tank and see what happens?
1997 nissan pathfinder -
i have no idea where the knock sensor is either, what other than a fauly gas cap can cause evap leak could this have to do ith muffler or feul filter , ? Thanks
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The muffler (exhaust system) or fuel fuel will not cause the P0440 code.
The knock sensor is under the intake plenum. Check the information: ( http://x.nissanhelp.com/for... ). You may be able to relocate the knock sensor.
Now, diagnosing the P0440 code is not easy. most of the times the problem is the gas cap, but if the gas cap is OK, you have a damage EVAP system hose or a leaking component. One common EVAP system component that leaks is the "EVAP Canister Purge Volumen Control Valve"
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bought my nissan maxima from a car auction and have had nothing but problems with y car i hate my car
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I don't know if anyone is still responding to this, but I have a 1996 Nissan Maxima. I replaced the Canister Purge valve, Canister Vent valve, pretty much every Evap valve, the hoses to those valves, evap/purge valve sensors, fuel tank pressure sensor, manifold air pressure sensor, and P0440 is the code that always pops up....... Damn you, P0440. The war continues...
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Did you check or replaced the canister? Sometimes water gets into the canister, and also, due to the mileage of your Maxima it's possible that the canister is already damage.
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Yes tha canister. Sounds like you may have a very small leak. Small leaks are not easy to find. The next step is to use an smog machine. You have to fill the entire EVAP system with smog and check where the is the leak.
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