Another idle issue

[MattiasJacobs]

Does your afr come back down after a bit? My car seemed to do this after hard or long runs but it would eventually come back down. I noticed my timing at idle jumping around so i figure my cas is walking out the door perhaps causing issues with my afr.

[Skym]

Sometimes that can be due an intake airleak near throttlebody on a GTS engine.

Jumping is probably the ECU using the idle stabilisation tables. ECU adjust's ignition timing roughly + or - 5 degrees. It's adjusting to match o2 sensor making ECU run rich, lean, then lean, rich and repeats. Also should notice MAF voltage fluctuating at same time.

I would think if that were the case it wouldn't be consistent. Also we were seeing up to 56 degrees during the tune. Here I don't see more than 54 and those are under boost. I would never see more than 36 at idle.
Appreciate the input though.

You're welcome. Oh, ok. Sometimes sensors fail or get dirty which makes them lazy (happens with o2 sensors, etc). I'm just posting the various area's that affect A/F ratio. It's a process of elimination.