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Jay, Nissan Technician
Category: Nissan
Satisfied Customers: 18552
Experience:  20+yrs experience with Nissan & Infiniti Trained & Certified.Currently still working for Dealer
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1998 nissan altima: canister..vent..control valve..continuity..sensors

Customer Question

My 1998 nissan altima keeps getting a ses code p1446(evap canister vent control valve closed). I checked to see if the valve is operating properly and it is. I changed every sensor and component in the evap system and checked for continuity in the plugs going to the sensors. I also cleaned the evap system with compressed air. Everything checks good, but I still keep getting the code (No gas over flow or out the back and no pump nozzle stopping too soon when I go to fill up). I'm stumped can you PLEASE help me out! Thanks
Submitted: 6 years ago.
Category: Nissan
Expert:  Nathan replied 6 years ago.
could you list each and every component you have replaced and or repaired.

I want to make sure something wasn't missed.
Customer: replied 6 years ago.
evap canister, evap pressure sensor, evap canister vent control valve, vacuum cut valve, vacuum cut bypass valve. I just changed the evap purge volume control valve today, but I havent test drove the car to see if the light comes back on
Expert:  Nathan replied 6 years ago.
Ok and did you insure that the line between the purge volume control valve and the canister was completely clear? Could you blow through it easily with your mouth?

Also did you replace all these components with new or used parts?

Double check the vacuum cut bypass cut valve and make sure it was installed correctly. I have seen alot of people install this valve upside down. The bracket that it clips into has a tab cut out of it in which the new bypass cut valve mates with to insure it is installed properly.

Customer: replied 6 years ago.
I replaced with used parts that I checked with a multimeter to make sure they were good. When I cleaned the evap system, I didnt find any clogged lines. Also the vacuum cut bypass cut valve is installed correctly.
Expert:  Nathan replied 6 years ago.
lets do this, you said you haven't driven the vehicle since the purge volume control valve was installed so go ahead and drive the vehicle for a couple of days and see if the code returns. I will leave this question open. When you confirm that there is or isn't a problem still let me know. We can then continue from there.
Customer: replied 6 years ago.
The light came on again. Does the ecu code p0325 (knock sensor) have anything to do with my problem?
Expert:  Nathan replied 6 years ago.

The p0325 code is completely unrelated to your problem. With everything you have already done there must be something you missed. I don't normally like to do this but I think it might be best if you have a dealership check it out for you to see what was missed.


I will OPT out so others can respond if they wish.

Expert:  Jay replied 6 years ago.
Hello and thank you for using

The code you have is for the Vent control valve. The most common thing for this is the vent control valve. I understand you said you have checked it. Did you apply voltage to it to get it to click? When it clicked did you see if the valve inside moved? The valve inside is what gets stuck or doesn't seal and causes the evap leak which throws the code. That and check the evap canister where the vent control valve bolts to it. I have seen the canister crack there.

If you have any more questions on this, please feel free to ask. Thanks Jay!
Customer: replied 6 years ago.
I think I found the proplem! My original charcoal canister is completely clogged (takes a couple days of driving to illuminate the service engine soon light). As for the other charcoal canister, I am able to blow very little air (from my mouth) through it (I covered the purge tube and blew through the gas tank tube on the charcoal canister and felt a little air coming out the vent control valve). This canister illuminates the check engine light within 10 min of driving. Also the can that is completely clogged is much more hevier than the other. How much air should be felt when blowing through the can as described above? Should it be free flowing or minimal effort?
Expert:  Jay replied 6 years ago.
Oh jezz, I never put my mouth to it. hehe. I am just telling you what I have seen most of the time.

I can tell you this. Remove the vent control valve completely. With a flash light and a small pick or screw driver, see if you can lift up the valve and make sure it moves very freely. Moisture normally rusts the valve part. So you can hear and feel it click, but the actual valve doesn't fully move or it's already stuck. When you remove it, it should be all the way down. If it's all the way up, don't try to free it up, it's just going to get stuck up there again.

With that valve we normally replace the canister also. Most cases the bolts that secure the vent control valve break in the canister.

If you have any more questions on this, please feel free to ask. Thanks Jay!

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