No brakes in the morning. It will definitely wake you up more than coffee.

[WyrTwister]

Check to see if the TB and every thing is secure . I think maybe the small hose may supply filtered air ( before it reaches the MAF sensor , to the engine . If so , that air circulates through the engine , purging fumes from the engine & is in turn pullet out through the PCV valve and into the intake manifold . All other air should be measured / sensed by the MAF sensor before it enters the throttle body .

If you have a air leak past the MAF , it is called Pirate Air , since it is not measured / sensed by the MAF & the computer does not " know " about it . This messes up the air fuel mixture , which the O2 sensor should pick up . The computer tweaks the idle air control valve and the air fuel mixture to try to correct , based on the info / data from the O2 sensors .

Or , something along these lines .

Check any electrical connectors on the IAC valve & TB . And any other parts that were disturbed .

How many miles did you say you had on the car ? Does sound like you are rebuilding the car 1 part at a time .

Ours is a 2015 Sonic . I hope , long term , it has fewer issues than the AVEOs .

God bless
Wyr

PS Check the hose clamps on the duct and any others you see . Check to see if any duct or hose has slid off its respective connector . Or sensor .