Replacing Electric Change-over Valve (SAI)
 

I was getting a CEL with codes for P0140 and p1411. Also the Blower for the Secondary Air Injection System was loud, like a vacuum cleaner with a blocked suction. First I replaced the blower, but that didn't change anything. Next after some research and double checking the vacuum lines I tried replacing the Electric Change-over Valve. I'm running fine with no CEL now and the blower is sounding normal.

Best access is by removing the alternator I kept it wired, but pulled it forward out of the way.
1. Remove the panel behind the seats.
2. Remove the serpentine belt.
3. the Alternator is held in with 2 bolts. The one on the right runs through an idler pulley.
4. With the alternator removed you can access most of the SAI system. The change-over valve is circled:
http://986forum.com/forums/uploads01...1432946527.jpg

The valve clips onto a bracket at the bottom. There are two vacuum lines and one electrical connection.
The hardest part was getting my big hands into position to connect the vacuum lines.
http://986forum.com/forums/uploads01/ECOV1432947003.jpg
There are a few more parts of the system, that can fail, or the passages in the SAI can be clogged, but this seems to have fixed it for me. I'd say #1 check the vacuum line for a leak before replacing other parts. While you are in there it's a good idea to replace all of the vacuum lines anyway if they are over 10 years old.

Here's the basic diagram, but layout varies by year and transmission:
http://986forum.com/forums/uploads01/sai1432951305.jpg

So based on your photo the change over valve is number 18 in the diagram?

Yes. Here is the same diagram, with the rest of the key appended.

http://986forum.com/forums/uploads01/sai1432955697.jpg


Clipped from this:
http://www.porsche.com/all/media/pdf/originalparts/usa/986_USA_KATALOG.pdf

edit: well, now that its uploaded that picture is scaled too small to read easily. Lets try adding this:
http://986forum.com/forums/uploads01...1432956097.jpg

Good work. What year is your box. I have an 99 and wondering if these part #s are good for me too.

That one is an 01. For the part number, check the Catalog.

The SAI is in the table of contents Under:
Main Group 1: Engine > 108: Air Injection System.

In the remarks column on the right, there are notes. -99 means through model year 1999, etc.