Yes, that big plastic hose on the bottom of your picture is the one I was referring to. Looks like it might be cracked from the photo. Since you took the MAF out, shine a good flashlight into that hose and then see if you can see any light leakage from around those pleated areas. Move the hose around a little to flex the pleats... if you see light then it is letting in unmetered (not gone through the MAF) air and will cause a rough idle and CEL.

That o-ring could also cause unmetered air if the o-ring is on the rear side of the MAF which it appears to be from the air flow arrow. Will need to be replaced.

Edit: Also wanted to add that I am not sure why your new idle problems were "caused" by an oil change. The only sources of vacuum leaks from that would be leaving the oil fill cap off the engine or not putting the dip stick back in. Both would be fairly obvious I would think.

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