CEL code P0440.. ?

[Gilles]

one week ago I got a CEL with the code P0440 (Fuel tank ventilation system),
which I erased with the Durametric but a week later (yesterday) it returned
but with an additional code # P0431 (Bank 2 catalyst warm up below threshold...

I looked up the PET and found out the P/N 997 201 251 00 (now 01) but the part cost $432... how can I check if this is the real cause for the code P0440 before buying an expensive part..?

.

[thstone]

Start by replacing the fuel cap. Its quick, cheap, easy and sometimes actually fixes the problem.

If not, then here is a link to the likely suspects. The fuel ventilation system is similar to the secondary air injection system in that there are several components and each needs to be tested to determine exactly which part has failed.

http://986forum.com/forums/general-discussions/46291-p0440.html

[Gilles]

Originally Posted by Gilles

one week ago I got a CEL with the code P0440 (Fuel tank ventilation system),
which I erased with the Durametric but a week later (yesterday) it returned
but with an additional code # P0431 (Bank 2 catalyst warm up below threshold...

I looked up the PET and found out the P/N 997 201 251 00 (now 01) but the part cost $432... how can I check if this is the real cause for the code P0440 before buying an expensive part..?

.

Stone, I will change first the fuel cap, it's got to be cheaper than the vent line...

[JFP in PA]

Originally Posted by Gilles

one week ago I got a CEL with the code P0440 (Fuel tank ventilation system),
which I erased with the Durametric but a week later (yesterday) it returned
but with an additional code # P0431 (Bank 2 catalyst warm up below threshold...

I looked up the PET and found out the P/N 997 201 251 00 (now 01) but the part cost $432... how can I check if this is the real cause for the code P0440 before buying an expensive part..?

.

P0440:

• Faulty EVAP canister purge valve
• Blocked fresh air line
• Leaking EVAP purge valve
• Leaking line between EVAP canister and intake
• EVAP purge valve incorrectly installed

[ohhh my]

Do you smell raw fuel? If so, it's probably a cracked at the top of the fuel tank. I forgot what it was called, but I had the same code and had it replaced and fixed all my problems.

[Gilles]

Originally Posted by JFP in PA

P0440:

• Faulty EVAP canister purge valve
• Blocked fresh air line
• Leaking EVAP purge valve
• Leaking line between EVAP canister and intake
• EVAP purge valve incorrectly installed

Thanks JFP..!

Do you think that the "Faulty EVAP canister purge valve" it is included on the hose #2 showing on the picture?

[JFP in PA]

Originally Posted by Gilles

Thanks JFP..!

Do you think that the "Faulty EVAP canister purge valve" it is included on the hose #2 showing on the picture?

No, it is on the other end of #6.

[Gilles]

Originally Posted by JFP in PA

No, it is on the other end of #6.

JFP,
Do you know if the canister purge valve is located by the fuel tank or by the engine compartment?
Thanks again!

[JFP in PA]

Originally Posted by Gilles

JFP,
Do you know if the canister purge valve is located by the fuel tank or by the engine compartment?
Thanks again!

It is under the intake manifold.

[Gilles]

Originally Posted by JFP in PA

It is under the intake manifold.

JFP, thanks for the heads up

Two or three weeks ago I was chasing an electrical issue and removed the throttle body with the IPD plennum to have access to the starter motor.

There is a possibility that I pulled too much the hose that connects to the bottom of the plennum,
if this is the same hose that connects to the Purge Valve, perhaps this could be the problem that is causing the leak on the purge valve and triggering the CEL...

Tomorrow after work I will remove the plennum to check for tight connections on the hoses.

Is there a way to check the proper operation of the Purge Valve..?

Thanks again!

Regards

[JFP in PA]

It is a simple valve that runs on 12V, you can bench test it with a small battery.

[Gilles]

Originally Posted by JFP in PA

It is a simple valve that runs on 12V, you can bench test it with a small battery.

Hello JFP, I cleared the CEL code P0440 a few times and still returns, and today decided to check the purge valve by disconnecting it from the throttle body and tried to create vacuum by suctioning into the hose and you cannot pull any air from it.

However, after activating the valve with the Durametric if you suck into the hose you gan get air (actually strong fumes) but the flow of air is Not constant, more like the valve is open and closing, is this valve is supposed to work intermittent or constantly open? I also noticed that you can blow air towards the valve but again, not a constant flow of air (I am not sure if I am explaining this clear or not.)

Your comments will be (as always), greatly appreciated.

PS: If the valve is indeed bad, could I install one of these on line, like this guy did it?
because the OEM valve for the '07 987 costs about $450…

Starts, Fires Up, Dies... - Page 5 - Pelican Parts Technical BBS

[JFP in PA]

Originally Posted by Gilles

Hello JFP, I cleared the CEL code P0440 a few times and still returns, and today decided to check the purge valve by disconnecting it from the throttle body and tried to create vacuum by suctioning into the hose and you cannot pull any air from it.

However, after activating the valve with the Durametric if you suck into the hose you gan get air (actually strong fumes) but the flow of air is Not constant, more like the valve is open and closing, is this valve is supposed to work intermittent or constantly open? I also noticed that you can blow air towards the valve but again, not a constant flow of air (I am not sure if I am explaining this clear or not.)

Your comments will be (as always), greatly appreciated.

PS: If the valve is indeed bad, could I install one of these on line, like this guy did it?
because the OEM valve for the '07 987 costs about $450…

Starts, Fires Up, Dies... - Page 5 - Pelican Parts Technical BBS

The valve should remain open while power is applied.

As for the valve in that article, I have no idea as I have never used one of them.

[Gilles]

Originally Posted by JFP in PA

The valve should remain open while power is applied.

As for the valve in that article, I have no idea as I have never used one of them.

Hello JFP, a gearhead friend of mine mentioned that the vent tube could have some fuel inside as a result of over filling, if this is correct, could be possible for me to disconnect the hose at the other end and blow some air through to remove the fuel?

I traced the hose on the engine compartment and it runs down in parallel to the power steering tubes that go to the front of the car, do you know if this hose have a connection somewhere that can be open? If so, I could disconnect it to try to remove the fuel inside, is this sounds logical?

Thank you for your comments!

[JFP in PA]

Originally Posted by Gilles

Hello JFP, a gearhead friend of mine mentioned that the vent tube could have some fuel inside as a result of over filling, if this is correct, could be possible for me to disconnect the hose at the other end and blow some air through to remove the fuel?

I traced the hose on the engine compartment and it runs down in parallel to the power steering tubes that go to the front of the car, do you know if this hose have a connection somewhere that can be open? If so, I could disconnect it to try to remove the fuel inside, is this sounds logical?

Thank you for your comments!

You won't find fuel in this line, but it can become plugged with carbon from the EVAP canister, so blowing it out with compressed air is a good idea.

This should help you with were the connections are:

[Gilles]

Originally Posted by JFP in PA

You won't find fuel in this line, but it can become plugged with carbon from the EVAP canister, so blowing it out with compressed air is a good idea.

This should help you with were the connections are:

JFP, Thank you for the diagram!

Before blowing compressed air through the vent line (at the intake plenum end with the purge valve energized), I should first disconnect the other end of the hose at the EVAP canister (by # 9) to avoid damaging something else, right?

Thanks again!

[JFP in PA]

Yes................