# EVAP Emission Control System Malfunction



## hnjeffers (Jun 8, 2005)

My check engine light came on today. Got the code checked and it is coming back PO440 EVAP Emission Control System Malfunction. Any clues what this is about? I drive a 98 Nissan Frontier 4x4 SE. Someone said it might be the fuel cap is not on tight enough............does this sound logical?


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## mikek2k5pathy (May 5, 2005)

Most likely when you get a code of PO440 it is the gas cap. It could either be loose, or not sealing properly. If you got gas with the engine running that can also set that code. Tighten the cap and give it a few days and the light will reset itself. Hope this helps.


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## hnjeffers (Jun 8, 2005)

I tightened the cap that day and the light is still on. Should I go have it cleared and see if it comes back on?



mikek2k5pathy said:


> Most likely when you get a code of PO440 it is the gas cap. It could either be loose, or not sealing properly. If you got gas with the engine running that can also set that code. Tighten the cap and give it a few days and the light will reset itself. Hope this helps.


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## mikeymaxima2001 (Jun 18, 2005)

yep i got that code today i just cleared it and hope id wont come back on haha


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## EZstreet (Jun 30, 2005)

*Having similar problem*

Hey all,

I have been getting several different EVAP related codes. Now I am down to just one and it I can not get rid of it. 

P0446 EVAP Emisson Control System Vent Circuit Malfunction

I have tried everything I know to fix it. I have replaced gas cap. I have removed the two Solenoid valves near the service port under the hood and removed the solenoid on the EVAP cannister. Hooked 12V to them all three and made sure the are working. I just don't know where to go from here. I don't understand the CIRCUIT part of this code. I was getting a code that said Canister Vent Control Valve but that one is gone. BTW- This is a 1998 Frontier 4X4.

Thanks in advance,

EZ


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## deanthompson (Jul 28, 2005)

Very good question, while this is not related to a frontier, I do have the same issue on my 97 pathfinder.
Doe's anyone have an idea on this?


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