PlasticStan

There's one on top of each spark plug : Seems to be a common problem on gts-t's.

Is the engine idle right, it should be 650rpm +/- 50rpm

You need to turn the CAS clockwise to retard the timing, sounds like yours is fully advanced! 15 deg is what it should be set at. Third white mark after the orange mark.

I installed my afr guage onto the ecu harness, much easier than running a wire into the engine bay. Simon.

You used automatic transmission fluid in a manual box? Is atf not too thick?