20 Most Recent 2001 Nissan Altima Questions & Answers

DTC P1441 means a warning about EVAP system flow during non purge condition.

This deals with the purge solenoid, vent solenoid, charcoal canister, all the vacuum lines in this system, as well as the gas cap. Any one of these components may contribute to this code being set. All the wiring should be tested including the connectors for any problems. Vacuum lines should be checked for cracks or loose connections. The canister may be damaged or not working properly.

However, the most common cause of this code on nissans is the evap vent control valve. It is located on the evap canister, under the rear of the car by the gas tank. Its the only electrical device attached to the canister itself.

Previously, there's a few things to check here. If you are sure that you don't have a wiring harness problem (these are notorious for the harness wearing through) then you need to check both the components that the code covers. This code covers both the vacuum cut valve bypass valve (the electronic solenoid) and the vacuum cut valve itself (small round plastic valve.) Here's a picture of both of them attached to each other:


If you are absolutely sure that the electronic solenoid is doing it's job, and that none of the hoses are pinched or blocked, you need to check the vacuum cut valve for functionality. Here's how you do that:


1. Plug port (C) and (D) with fingers.
2. Apply vacuum to port (A) and check that there is no suction from port (B).
3. Apply vacuum to port (B) and check that there is suction from port (A).
4. Blow air in port (B) and check that there is a resistance to flow out of port (A).
5. Open port (C) and (D).
6. Blow air in port (A) check that air flows freely out of port (C).
7. Blow air in port (B) check that air flows freely out of port (D).

Also check to make sure that all hoses are going to the correct places.

Keep in mind that the P1441 is a very hard code to diagnose, as it's very "general". There are a list of things that can cause this code, and there is a TSB (Technical Service Bulletin) issued by Nissan that states it can even be faulty ECM (Engine Control Module or On-board computer) programming.

Here is a list of possilble causes:
Incorrect fuel tank vacuum relief valve
Incorrect fuel filler cap used
Fuel filler cap remains open or fails to close.
Foreign matter caught in fuel filler cap.
Leak is in line between intake manifold and EVAP canister purge volume control solenoid valve.
Foreign matter caught in EVAP canister vent control valve.
EVAP canister or fuel tank leaks
EVAP purge line (pipe and rubber tube) leaks
EVAP purge line rubber tube bent.
Blocked or bent rubber tube to EVAP control system pressure sensor
Loose or disconnected rubber tube
EVAP canister vent control valve and the circuit
EVAP canister purge volume control solenoid valve
Absolute pressure sensor
Fuel tank temperature sensor
O-ring of EVAP canister vent control valve is missing or damaged.
Water separator
EVAP canister is saturated with water.
Fuel level sensor and the circuit
EVAP control system pressure sensor

Here is the TSB issued by Nissan...
Classification: EC00-018a
Reference: NTB00-059A
Date: August 30, 2000

APPLIED VEHICLE: 2001 Pathfinder(R50)
If an applied vehicle has a MIL "ON" with DTC P1441 (EVAP Very Small Leak) stored in Engine Self Diagnosis results, the cause may be the ECM program.

There is an updated ECM program available to address this incident if it should occur.

Hope this helps; keep us updated about your advance.

2001 Nissan... | Answered on May 08, 2019

On the engine,one at the top rad hose connection and one in the lower.

2001 Nissan... | Answered on Mar 21, 2018

Hi There,
Chances are the cooling systems requires "bleeding". Meaning there is a pocket of air in the hoses where your sensor is.
Dependent upon the car maker, there are specific instructions on rectifying this problem.
If your car is an vintage car (about 30 years or more), then the thermostat could be playing up (stuck), and needs replacing.
Good luck!

2001 Nissan... | Answered on Feb 10, 2018

I'd need to see the pressure when it's kicking off. If the pressure is on the edge, it can cause it to drop on cooler days where the low pressure switch shuts it down. How do you know what charge is in it? Did you evacuate and fill with a scale? You CANNOT judge charge based on pressure alone. Impossible

2001 Nissan... | Answered on Jan 14, 2018

So you want us to post about 75 diagrams for you so you can save the cost of a shop manual.

2001 Nissan... | Answered on Jan 09, 2018

If it will move in every other direction I would start by looking under the seat and check down in the seat trac for something lodged in it way.

2001 Nissan... | Answered on Dec 12, 2017

When a car overheats it can do serious damage to the engine internals, including completely seizing the engine. It is common for overheating to blow a head gasket which would explain the bad starting. Unless you know how to diagnose these issues, you will need to take it to a repairer for an assessment. Be prepared for some very bad news.

2001 Nissan... | Answered on Jul 09, 2017

could be the bad catalytic converter.

2001 Nissan... | Answered on Jun 29, 2017

For a free check on your code,go to Autozone and they will scan your code for free and it only takes a minute and they will tell you what's wrong.When was the last time you had your oil changed.You can take it to the Nissan Dealership for a oil change and they will see the check engine light on and run a free scan and tell you what is wrong and how much it will cost.They always check customer's vehicle's out to see if it need's anything.

2001 Nissan... | Answered on Jun 02, 2017

I would suggest having the fault codes read and check for a problem torque converter clutch servo/ solenoid problem
could be a bad connection but from your description that will be the area of concern

2001 Nissan... | Answered on Mar 13, 2017

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