p0446

[goanx]

Can somebody help me. I have a 99 996 with 76K miles on it. The CEL keeps coming on with the same code. Not sure what I need to do. I checked out this forum and there is nothing too specific on how to fix it myself. It does nto seem like a difficult problem to remedy and was hoping someone here could walk me through it.

This forum was great for replacing or cleaning out my MAF and re-installing it. I was looking for some direction with clearing out this CEL and do not want to take it to my mechanic as he is getting really rich off me.

thanks for any help.

[Loren]

:welcome:

P0446 EVAP Canister Shutoff Valve (Function) - Below Lower Limit

Potential causes:

- Purge air line blocked.

- Flow resistance of EVAP canister too high.

This says you are failing the fuel tank (sealing) test. Look for a loose gas cap (or bad o-ring seal) or one of the causes above.

[goanx]

Where would the O-ring seal be. I actually changed out my fuel cap and this has not helped. I do not get great mileage on my car since I got it. About 250 miles per full tank. Is that normal.. If I am failing the fuel tank sealing test - waht does that mean.

Are some of the things you listed things I can change or remedy myself and if I can could you please tell me how I could do it.

Much appreciated.

P0446 EVAP Canister Shutoff Valve (Function) - Below Lower Limit

Potential causes:

- Purge air line blocked.

- Flow resistance of EVAP canister too high.

:welcome:

P0446 EVAP Canister Shutoff Valve (Function) - Below Lower Limit

Potential causes:

- Purge air line blocked.

- Flow resistance of EVAP canister too high.

This says you are failing the fuel tank (sealing) test. Look for a loose gas cap (or bad o-ring seal) or one of the causes above.

[Loren]

The o-ring is on the gas cap. If your new gas cap did not have one you need to get one.

On US cars the EPA requires that cars pass a fuel vapor leak test prior to operating. So each time your key is turned the EVAP system in your car tests the integrity of the fuel vapor system to make sure you are not leaking fuel vapor into the air. I don't remember what year this rule went into effect but it has been in all US cars for at least 5 or 10 years.

If it turns out not be the gas cap (or it's o-ring seal) then you need to do a search here for further troubleshooting tips.

Also, please remember once the problem is corrected, unless you turn the CEL off with a diagnostic tool it can take two or three days of driving (drive cycles as prescribed by the EPA) for it to go off by itself.

[goanx]

The o-ring is on the gas cap. If your new gas cap did not have one you need to get one.

On US cars the EPA requires that cars pass a fuel vapor leak test prior to operating. So each time your key is turned the EVAP system in your car tests the integrity of the fuel vapor system to make sure you are not leaking fuel vapor into the air. I don't remember what year this rule went into effect but it has been in all US cars for at least 5 or 10 years.

If it turns out not be the gas cap (or it's o-ring seal) then you need to do a search here for further troubleshooting tips.

Also, please remember once the problem is corrected, unless you turn the CEL off with a diagnostic tool it can take two or three days of driving (drive cycles as prescribed by the EPA) for it to go off by itself.

I am quite sure I got the gas cap with the O-rings. I twist it 3 clicks to tighten the cap however the CEL light keeps coming on with teh errror code P0446 on it. I also use the ODB-II tool and erase every time but it has been coming on a lot more often now. Not sure if there are any other DIY fixes I can do before I succumb to taking it to a dealer to have ti looked at. Is there anything else I can do? Any help is greatly appreciated.

[Loren]

Check purge air line for blockage.

1. Remove front right-hand wheel housing liner.

2. Detach purge air line (connection face up) from EVAP canister.

3. Blow through purge air line with compressed air.

[goanx]

Check purge air line for blockage.

1. Remove front right-hand wheel housing liner.

2. Detach purge air line (connection face up) from EVAP canister.

3. Blow through purge air line with compressed air.

Do you have any diagrams or some such that would allow me to follow step by step the removal of the wheel housing liner and what to look for once removed. Much appreciated.

[Loren]

Check purge air line for blockage.

1. Remove front right-hand wheel housing liner.

2. Detach purge air line (connection face up) from EVAP canister.

3. Blow through purge air line with compressed air.

Do you have any diagrams or some such that would allow me to follow step by step the removal of the wheel housing liner and what to look for once removed. Much appreciated.

Have you tried the site Search?

There are at least a half dozen threads on P0446.

[JeTexas]

This morning I hooked the Durametric up just to record some live numbers for another forum member, and I was surprosed to get the P0446.

No CEL, just the code in the reader:

P0446 Fault Code 95 - shutoff valve activated

Charcoal filter (function)

I cleared it, and it didn't immediately come back on, but is it telling me that the charcoal element in my EVAP canister is pretty much done?

[Loren]

This morning I hooked the Durametric up just to record some live numbers for another forum member, and I was surprosed to get the P0446.

No CEL, just the code in the reader:

P0446 Fault Code 95 - shutoff valve activated

Charcoal filter (function)

I cleared it, and it didn't immediately come back on, but is it telling me that the charcoal element in my EVAP canister is pretty much done?

P0446 EVAP Canister Shutoff Valve (Function) - Below Lower Limit

Potential caues:

- Purge air line blocked.

- Flow resistance of EVAP canister too high.

So if the line not plugged then your canister may be bad.