Evaporative Canister Question

[Pierre's Porsche]

So my 2000 Boxster base, threw CEL code P0446 this week. I'v followed the posts and checked with the Service Manual and know what that code means but there is a question....

For about four weeks prior to thowing the CEL, i had been noticing two things: 1. just after cold start in the morning, while backing out of my garage, notice strong smell of gasoline; and 2. at almost every stop sign, I'd hear a single knock,(sometimes two a couple minutes apart) coming from right front wheel well location. I have assumed the knock was simply the EVAP canister shut off valve opening or closing.

However, in the past two days since I reset the CEL, which has not yet come back on, I no longer smell the gas or hear the knock (I've been paying close attention).

Do you think this means the EVAP canister shut off valve has finally failed, in the closed position..? Thus the code..?

I'm going to wait until my next gas tank fill to see if the CEL/code returns. Yes, CEL came on 20 miles after a fill up.

My first step will be to "jump" the cansiter shut off valve to check if it operates when directly connected to a power source. Or is there another way to check functionality of shut off valve.

Thanks.

[Loren]

P0446 EVAP Canister Shutoff Valve (Function) – Below Limit

Possible causes:

– Purge air line blocked

– Flow resistance of EVAP canister too high

[Pierre's Porsche]

Thanks Loren, but in my first line I stated I know this already.... I can use your advise/opinion on the second paragraph of my post....it's all about the knock and smell of gas.

[Loren]

You need to start by checking to see if the purge line is blocked - that was my point.

[bar10dah]

I had this code also. I pulled the top connection off the EVAP canister and blew compressed air through it. That code hasn't returned yet.

[mcmike27]

I have had this fault on 2 occasions...on the 1st the dealer blew out the evap line with compressed air....all good..the next time it happend I overfilled the gas tank and it threw the code. I reset it and am wary about overfilling the tank at the gas station. It hasnt reoccured

:)

[Pierre's Porsche]

Bar, or Loren,

I got to looking at the evap canister this weekend with the idea of blowing out the purge air line. However, my Evap canisister did no match the diagrams provided in other forum discussions on this topic.

The diagram showed one line on top and two coming out the bottom. My cansister has three lines coming out of the top. Which of the three lines is the air vent to blow out? (left, middle, or right, looking straight at the cansister from within the wheel well)...? Two of the lines leave the cansister and are routed back toward the fuel tank. The third line (right) goes from the cansister back toward the front/top of the wheel well to a "block" with two lines going in and out of it...(appears to be the shut off valve housing, as again, unlike the diagram, my s/o valve appears to be separate from the canister....

I blew air into two of the lines but based on the bubbling sound appeared to be pushing air back into the fuel tank... HELP!

[Loren]

Bar, or Loren,

I got to looking at the evap canister this weekend with the idea of blowing out the purge air line. However, my Evap canisister did no match the diagrams provided in other forum discussions on this topic.

The diagram showed one line on top and two coming out the bottom. My cansister has three lines coming out of the top. Which of the three lines is the air vent to blow out? (left, middle, or right, looking straight at the cansister from within the wheel well)...? Two of the lines leave the cansister and are routed back toward the fuel tank. The third line (right) goes from the cansister back toward the front/top of the wheel well to a "block" with two lines going in and out of it...(appears to be the shut off valve housing, as again, unlike the diagram, my s/o valve appears to be separate from the canister....

I blew air into two of the lines but based on the bubbling sound appeared to be pushing air back into the fuel tank... HELP!

Exact model and year of your car please.

[Pierre's Porsche]

MY 2000 Boxster 986 with base 2.7L. No engine mods as far as I know.

[Loren]

Does your canister look like this one? If so, it should be the small line at the top.

[Pierre's Porsche]

No it does not. My canister has no lines coming out of the bottom. There is one smaller line (approx OD 3/8") are two "big" (approx 3/4" OD) lines, left to right, respectively, coming out of the top all in a row.

[Loren]

It will likely still be the smaller line.

[sak_27]

Loren,

I have a 1999 986, 2.5L. I have been getting P0446 code for a while and took it to a mechanic to get it checked out. After testing they believe the issue is with the canister itself. Do you know the part number of the EVAP canister for my car? I am getting a 2 or 3 different part numbers and the price is ranging from ~ $240 - $650. Thanks

sak

[Loren]

Loren,

I have a 1999 986, 2.5L. I have been getting P0446 code for a while and took it to a mechanic to get it checked out. After testing they believe the issue is with the canister itself. Do you know the part number of the EVAP canister for my car? I am getting a 2 or 3 different part numbers and the price is ranging from ~ $240 - $650. Thanks

sak

Check your option codes:

if your car has M660 then use 996-201-221-03 Carbon Cannister -- US MSRP $594.33

if your car has M664 then use 996-201-221-07 Carbon Cannister -- US MSRP $237.33

If you can not find your option codes then send me PM with your VIN and I will look it up for you.

[sak_27]

Thanks Loren. I will go home today and check. For reference sake, what are the M660 and M664 options?

sak

[Loren]

M660 - OBD 2

M664 - ORVR

During MY1998 and 1999 both were sold.

[Randy_K]

Loren,

I have a 1999 986, 2.5L. I have been getting P0446 code for a while and took it to a mechanic to get it checked out. After testing they believe the issue is with the canister itself. Do you know the part number of the EVAP canister for my car? I am getting a 2 or 3 different part numbers and the price is ranging from ~ $240 - $650. Thanks

sak

Check your option codes:

if your car has M660 then use 996-201-221-03 Carbon Cannister -- US MSRP $594.33

if your car has M664 then use 996-201-221-07 Carbon Cannister -- US MSRP $237.33

If you can not find your option codes then send me PM with your VIN and I will look it up for you.

Just FYI SAK. mine has part number 996-201-221-03 and that's the one with the line out the bottom. And just my luck the more expensive of the two. I'm getting the same P0446 code.

Randy

PS Call Sunset Porsche for pricing. I received quotes for consideribly less than MSRP.

Edited May 6, 2012 by Randy_K

[sak_27]

Turns out I have the OBD2 (the more expensive version). I will be making a call to Sunset very soon.

[denvergold]

I had this code also. I pulled the top connection off the EVAP canister and blew compressed air through it. That code hasn't returned yet.

What's the best way to get to the EVAP canister to blow compressed air through it? Also, do you have to disconnect the other end that connects to the intake manifold?

Thanks Dean

dean@goldenreturnscapital.com

[bar10dah]

Yes, take the liner out. It will make it easier.

There's really no way to disconnect the other end, as there's a valve on the other end. And, from what I've read, you can blow this line out either way, from the front or the back. However, I would blow it from the EVAP canister side. It's my opinion it's better to blow out in the direction the air would be flowing. And, if you do dislodge anything, it'll blow into the intake system and be burned during combustion. If you blow from the engine side, if there was a blockage, you'd just be blowing it back into the EVAP canister and it might block the line again.

[Loren]

I agree - taking the liner out is a 5 minute job once the wheel is removed.

[prash_142]

I have P0446 code. 1998 Porsche Boxster. I haven't tried to blow compressed air yet.

But I am considering to replace the 'purge valve'. Has anyone done it and has photos? 

 

I am thinking the part labeled '1' in the document 986 DME 5.2 P0446.pdf

 

where can I locate this valve? I have read somewhere that this can be accessed through the Engine compartment below the intake manifold. Is this correct?

Photos would help I believe.. 

 

If I were to blow air into this line and to 'intake manifold' area, which connection from cannister should I blow compressed air?

[JFP in PA]

I have P0446 code. 1998 Porsche Boxster. I haven't tried to blow compressed air yet.

But I am considering to replace the 'purge valve'. Has anyone done it and has photos? 

 

I am thinking the part labeled '1' in the document 986 DME 5.2 P0446.pdf

 

where can I locate this valve? I have read somewhere that this can be accessed through the Engine compartment below the intake manifold. Is this correct?

Photos would help I believe.. 

 

If I were to blow air into this line and to 'intake manifold' area, which connection from cannister should I blow compressed air?

 

That valve is under the intake runners.  You need to blow out the entire line attached to it as well.

[bar10dah]

I've done it. It sucks. The intake plenum needs to come out. If you're mechanically inclined, should take close to a hour to get to the check valve. Then after remove/replace, take another hour to get it all back together.

When I removed my check valve, the insides were rusted and corroded. Air blew both ways, so no longer a "check valve." Pain in the butt, but after replacement, and blowing out the lines, never had 0446 come back again.

[HELLAS59]

I've done it. It sucks. The intake plenum needs to come out. If you're mechanically inclined, should take close to a hour to get to the check valve. Then after remove/replace, take another hour to get it all back together.

When I removed my check valve, the insides were rusted and corroded. Air blew both ways, so no longer a "check valve." Pain in the butt, but after replacement, and blowing out the lines, never had 0446 come back again.

How did you know that the check valve needed to be replaced, and on which line did you blow compressed air?