Running Lean - What's leaking in this smoke test?

2006 Tundra 4.7, DC, 2WD, 220k miles

CEL for running lean on bank 2 -- but both banks have high long term fuel trim ~20-25%

I hooked a smoke machine up to the intake with the throttle closed, and smoke is coming from the pictured areas. I can't see obvious vacuum lines here. Could this be the intake gasket? Could this be the vacuum leak? Thank you.

 

It kinda looks like it’s leaking from the intake manifold sits, maybe the intake manifold gasket is leaking, if you pore tiny drops of water near the area, the idle should change, you would be able to hear the idle changing or you can even use a automotive stethoscope to listen to the suction

 

Hi zgurrola21, thanks for your reply. I'll try spraying water around it. I don't know what intake manifold sits are. Does that mean the manifold could be cracked? Other pictures I see online have the manifold looking aluminum and mine is plastic -- not sure if that's after market.

 

I'm not sure about using water. Seems sketchy to me. I've always heard using flammable carburetor cleaner and spraying that around the area and seeing if idle changes.

 

It’s super dangerous to use carb cleaner, highly flammable, it’s only small drops but you can also use which is my favorite is using a automotive stethoscope to listen to the leak

 

The other tried method is raw propane gas out of a torch with a hose to pin point the leak.

 

That's what I've always done.. Works like a charm.