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I have a P1443 code and I've replaced my canister and the code still persists. Rodents ate the fuel line and some hoses but I can't find a leak and have no clue how to test the voltage of the sensors.
I have a 96 4 cylinder Ranger and really need this code to be fixed. Can someone recommend a good mechanic is the philly/Delaware/SJ area?
Thanks
Last edited by Jlong1983; Aug 9, 2023 at 04:44 PM.
P1443 Evaporative Emission System Control Valve (low/no flow)
This code will not cause any running issue
EVAP system creates a slight Negative pressure in the gas tank when engine is running, it uses engine Vacuum to do this
It is there to suck out gasoline fumes that occur when driving and the gasoline is sloshing back and forth in the tank
Its an emissions system
It pulls the gasoline vapor thru the charcoal canister and into the engine's intake to be burned
To work correctly the gas tank needs to be sealed, so negative pressure can be applied
The code basically means negative pressure can't be detected by the Purge sensor, one engine is running
Do this simple test first
Get a hose and a damp towel or rag
Remove gas cap
Put hose in the tank opening and wrap towel around it to seal the tank, hold it tight with your hand
Blow into the hose
Listen for air leaking out, a helper is nice to either listen or blow
There were 2 hoses on the charcoal canister, these hoses can get rotten and crack, so leak and you get that code or others
One runs back to the gas tank
One runs to the engine, and there is an electric valve on this hose and also a valve/sensor at the engine on this same hose
You can remove the hose to the tank at the canister and plug it with a bolt or tape, then redo the test with the hose and rag, the tank should now hold pressure as you blow into it, if not you should HEAR the air leaking out and where, filler hose is common, but if there were rats............then anywhere along that hose that goes from the top of the tank to the canister, but you should HEAR it
The Canister purge valve, first one, nearest the canister, can get charcoal bits sucked inside its valve, its just a 12volt valve you can test it with a 9v battery, should "click" when its 2 prongs get + and - from battery, there is no + or - prong it works when connected either way
Purge Flow sensor, on the engine, is not as easy to test so its a replacement part when it comes down to it
You would SMELL it if rats ate the fuel lines, and this wouldn't cause P1443 in any case
I should have been more clear, the rodents also chewed the lines around the canister purge valve, and yes those had been replaced. I did try the blowing into the gas tank but i did not hear anything, i can try to isolate each hose. everything below you mentioned about the battery as a test as a test is beyond my skill level unless i can find a youtube video. I'll try to isolate each hose and give it a go tomorrow.
Originally Posted by RonD
P1443 Evaporative Emission System Control Valve (low/no flow)
This code will not cause any running issue
EVAP system creates a slight Negative pressure in the gas tank when engine is running, it uses engine Vacuum to do this
It is there to suck out gasoline fumes that occur when driving and the gasoline is sloshing back and forth in the tank
Its an emissions system
It pulls the gasoline vapor thru the charcoal canister and into the engine's intake to be burned
To work correctly the gas tank needs to be sealed, so negative pressure can be applied
The code basically means negative pressure can't be detected by the Purge sensor, one engine is running
Do this simple test first
Get a hose and a damp towel or rag
Remove gas cap
Put hose in the tank opening and wrap towel around it to seal the tank, hold it tight with your hand
Blow into the hose
Listen for air leaking out, a helper is nice to either listen or blow
There were 2 hoses on the charcoal canister, these hoses can get rotten and crack, so leak and you get that code or others
One runs back to the gas tank
One runs to the engine, and there is an electric valve on this hose and also a valve/sensor at the engine on this same hose
You can remove the hose to the tank at the canister and plug it with a bolt or tape, then redo the test with the hose and rag, the tank should now hold pressure as you blow into it, if not you should HEAR the air leaking out and where, filler hose is common, but if there were rats............then anywhere along that hose that goes from the top of the tank to the canister, but you should HEAR it
The Canister purge valve, first one, nearest the canister, can get charcoal bits sucked inside its valve, its just a 12volt valve you can test it with a 9v battery, should "click" when its 2 prongs get + and - from battery, there is no + or - prong it works when connected either way
Purge Flow sensor, on the engine, is not as easy to test so its a replacement part when it comes down to it
You would SMELL it if rats ate the fuel lines, and this wouldn't cause P1443 in any case
Okay, did the hose test and everything held pressure. What we did notice was based on the diagram you sent that the canister and purge valve senor was in opposite order. So, we flipped those and did the air test again and everything held.
I reset the battery and the engine light came back on tonight. I just order a new pv324, the purge valve sensor and it should be here Wednesday, after that I've replaced the hoses, the sensor, the canister, the gas cap. I'm pretty much at my whits end here.
Here is the old
Here is the new. I'm assuming I but these on in the correct direction? My friend said the arrow points towards the charcoal cannister...
P1443 Evaporative Emission System Control Valve (low/no flow)
This code will not cause any running issue
EVAP system creates a slight Negative pressure in the gas tank when engine is running, it uses engine Vacuum to do this
It is there to suck out gasoline fumes that occur when driving and the gasoline is sloshing back and forth in the tank
Its an emissions system
It pulls the gasoline vapor thru the charcoal canister and into the engine's intake to be burned
To work correctly the gas tank needs to be sealed, so negative pressure can be applied
The code basically means negative pressure can't be detected by the Purge sensor, one engine is running
Do this simple test first
Get a hose and a damp towel or rag
Remove gas cap
Put hose in the tank opening and wrap towel around it to seal the tank, hold it tight with your hand
Blow into the hose
Listen for air leaking out, a helper is nice to either listen or blow
There were 2 hoses on the charcoal canister, these hoses can get rotten and crack, so leak and you get that code or others
One runs back to the gas tank
One runs to the engine, and there is an electric valve on this hose and also a valve/sensor at the engine on this same hose
You can remove the hose to the tank at the canister and plug it with a bolt or tape, then redo the test with the hose and rag, the tank should now hold pressure as you blow into it, if not you should HEAR the air leaking out and where, filler hose is common, but if there were rats............then anywhere along that hose that goes from the top of the tank to the canister, but you should HEAR it
The Canister purge valve, first one, nearest the canister, can get charcoal bits sucked inside its valve, its just a 12volt valve you can test it with a 9v battery, should "click" when its 2 prongs get + and - from battery, there is no + or - prong it works when connected either way
Purge Flow sensor, on the engine, is not as easy to test so its a replacement part when it comes down to it
You would SMELL it if rats ate the fuel lines, and this wouldn't cause P1443 in any case
Thanks RonD, sorry for the delay I just had a chance this week to circle back around to this.
I am able to blow into the gas tank with a hose and it holds pressure and everything with a blue X has been replaced with new parts. The P1443 Code is still on and I'm completely baffled.
In your diagram the Evaporative Canister Purge Valve would be the most likely issue for P1443
Generally it comes as "an assembly" with the 2 hoses attached
In any case its a 12v solenoid valve that the computer uses to apply vacuum to the canister and gas tank
"New" just means NEVER EVER TESTED now-a-days, not it works
So with so many "new" parts you may be chasing your tail
I would test the new valve with a 9v battery or jumper wires from the car battery
Unplug it
Inside there are 2 terminals, there is no polarity, no + or - terminal, as long as 1 is + and the other - then solenoid will "click" open
If no click then new part is bad
I have a P1443 code and I've replaced my canister and the code still persists. Rodents ate the fuel line and some hoses but I can't find a leak and have no clue how to test the voltage of the sensors.
I have a 96 4 cylinder Ranger and really need this code to be fixed. Can someone recommend a good mechanic is the philly/Delaware/SJ area?
Thanks
Did you end up getting this fixed? If filler neck is really messed up it can throw this code. Does any fuel spill out when you fill up?
