how do u find the vacuum leak/where do u look when u know u have one.....idle surging

 

Listen for a whistling noise as air is sucking into the leak. Common places you can check are...

throttle shaft
throttlebody gasket
injector seals where they stick into the manifold
manifold gasket against head
gaskets where IACV mounts to manifold
brake booster
ANY of those zillion little vacuum hoses...

since it's a gsr, you also have...
secondary butterfly (IAB) shaft
gasket where intake manifold comes apart near IAB butterflys