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

[Strawfordt]

Does anyone know what this means to me and what i will likely have to do to fix it?


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

I get the code intermittently. Cleared iut twice and now it is back again.

My Box is a 98, 2.5L

Help appreciated.

Thanks

[MNBoxster]

Hi,

The Posche Diagnostic procedure for P0446 states:

• Possible Causes of Fault:
  
  - Air line plugged
  
  - Tank Vent stuck in the open state (vacuum continuously enters the Tank System from the Intake pipe)
  
  - Activated Charcoal Shutoff Valve is plugged/stuck in a closed state
  
  - Flow resistance of the Activated Charcoal Filter is too high (Filter deformed/plugged)
  
  - Pressure Sensor closes incorrectly (Polarity reversal)

The procedure then goes on to say to replace the Activated Charcoal Cannister, if previously replaced, replace the Shutoff Valve. There is also a procedure to blow compressed air into the Purge Air Line. Most of these components live under the Passenger side Front Wheel Well Liner. Hope this helps...

Happy Motoring!... Jim'99

[Strawfordt]

Jim,

My problem is intermittent. Does that help narrow down possible root causes?

Thanks

[MNBoxster]

Originally Posted by Strawfordt

Jim,

My problem is intermittent. Does that help narrow down possible root causes?

Thanks

Hi,

Well it does somewhat. A plugged Purge Air Line or a polarity reversal to the Pressure Sensor would not be intermittent things - they either are or are not, which eliminates them as possibilities.

That leaves you with the Activated Charcoal Cannister or Shutoff Valve. I'm betting on the Cannister as the most likely culprit, especially on a '98. Hope this helps...

Happy Motoring... Jim'99

[Strawfordt]

Originally Posted by MNBoxster

Hi,

Well it does somewhat. A plugged Purge Air Line or a polarity reversal to the Pressure Sensor would not be intermittent things - they either are or are not, which eliminates them as possibilities.

That leaves you with the Activated Charcoal Cannister or Shutoff Valve. I'm betting on the Cannister as the most likely culprit, especially on a '98. Hope this helps...

Happy Motoring... Jim'99

Jim,

Sorry for all the bother but I am travelling in China right now and cannot get pricing on these components. Do you have any idea on the cost of each and the time to repair?

Thanks again,

Tom

Tom

[MNBoxster]

Originally Posted by Strawfordt

Jim,

Sorry for all the bother but I am travelling in China right now and cannot get pricing on these components. Do you have any idea on the cost of each and the time to repair?

Thanks again,

Tom

Tom

Hi,

The Activated Charcoal Cannister, PN# 996.201.221.05 should be under $200 USD and the Shut-off Valve, PN# 996.605.201.01 should be under $125USD. Hope this helps...

Happy Motoring!... Jim'99

[BrakeExpert]

Ive had this code on two Boxsters and replacing the gas cap fixed both of them. Check your gas cap and see if the rubber is deteriorated around the outside. Just saying that because its a far cheaper fix.