P1411, P0410 & Diverter Valves

[jporter]

I have a stock 2001 996 TT

I had the CEL come on over the weekend and the codes were P1411 and P0410. I'm familiar with this issue as I fixed a secondary air problem with my prior car that was a Boxster. In doing some research on the TT I found that replacing the diverter valves (called shut-off valves in PET) have fixed this problem for some people. The fan does run at startup so I decided to do a quick check on the diverter valves - suck on a hose attached to the hose connector on top of the valves. One of the valves could hold the vacuum, but the other could not - of course the bad one is the one toward the front of the car. I have the following questions / request for comment.

Do I need to replace both diverter valves or can I just replace the bad one?

It looks like the diverter valves vacuum hose is related to the secondary air vacuum lines and wondered if anyone had any comments on whether a bad diverter valve could cause the codes listed above.

Edited August 16, 2010 by jporter

[gpt817]

I have a stock 2001 996 TT

I had the CEL come on over the weekend and the codes were P1411 and P0410. I'm familiar with this issue as I fixed a secondary air problem with my prior car that was a Boxster. In doing some research on the TT I found that replacing the diverter valves (called shut-off valves in PET) have fixed this problem for some people. The fan does run at startup so I decided to do a quick check on the diverter valves - suck on a hose attached to the hose connector on top of the valves. One of the valves could hold the vacuum, but the other could not - of course the bad one is the one toward the front of the car. I have the following questions / request for comment.

Do I need to replace both diverter valves or can I just replace the bad one?

It looks like the diverter valves vacuum hose is related to the secondary air vacuum lines and wondered if anyone had any comments on whether a bad diverter valve could cause the codes listed above.

If you cam get a new diverter valve, just replace the bad one and see what happens. If it still doesnt hold the vaccum, then get another one. I replaced mine with Agency Power DVs and I didnt have any problem. It cost around $260+.

[jporter]

I replaced the diverter valve last night and decided that there is an evil spirit in the mind of the person that oriented the hose clamps so that they could not be reached by any tool known to mankind. Fortunately the mounting is flexible enough to get a clamp tool with an extension in to release them. I will add to this post if the P1411 and P0410 codes reappear.

[jporter]

It's been a couple months since I replaced the diverter valve and the codes have not reappeared. The attached image shows the relationship of the diverter valves to the air injection system.

[jpflip]

Good job jporter. I did the same thing (Agency power valves) but I've lower the engine to get more access. I also did a leak check and found two small leaks in this maze of sense line....

[KevinMac]

Had a similar issue with my 2002 996t, but in this case was a P0491 secondary air valve circuit. along with a moosing sound on cold startup! Well to make a long story short, the required vacuum of 20lbs was only at 16, so in essence the SAV was not getting enough, making the internal diaphram resonate. One divertor valve was starting to leak. It is recommended you go after market with the divertor valves since te Bosch OEMs are known to fail. I went to Champion for the pair ( Forge),with 90 degree vacuum connections, cost was $350 for the pair. They are much larger and fixed the issue!