Vacuum Check valve location?
 

So I'm going to replace my vacuum check valve as I think it might be part of the problem for my starting issues, I found some on eBay for about $10, but where is it located? It's a 98.5 A4 1.8TQ

By the airbox. Take off the top cover and it should be near the back of the airbox.

Ok so take off the air box (passenger side infront of firewall correct?)top and ill see it?

You should see this

http://files.chronosinteractive.com/...fault17519.jpg

Ok cool thanks!

There are an additional 2 check valves near/under the intake manifold. And there's a slightly larger black check valve at the back of the intake manifold for the brake booster.

Which one should I replace? I was told the check valve could be causing my long start up times