Check engine light + Hissing noise

[mcgill_redmen]

Hello
Went to an Toyota dealer last Friday for an spark plug change " Tune Up",
next day check engine light came on, I discover air filter box some hose wasn't connected, after re-connected check engine light disappear, but re-appears shortly and I heard some tiny high pitch sound and hissing noise near the passenger side, and what might be the cause? I'll surely bring back to dealer on Monday.
This is for an v6 Camry with 1mzfe engine.

[Tech1984]

Sounds like the PCV hose has come loose or a cracked pcv valve

[SumairM]

check the vacuum hoses

[mcgill_redmen]

I took the cover off and saw the vacuum hose, it seems tight, but the sound come near the pvc valve and it look tight too, but the hissing and choking symptom is from that area. There's also an check engine light on, i guess after tune up at dealership they broke something and will go and see them again.

Updates: It was the vacuum hose connected to the manifold, the other side connected to the pvc valve was tight and snug.
Now the hissing and choking symptom is gone and I'am happy. But check engine light still on, and will have a word with the tech advisor and the repairmen for this mistakes.

Thanks for everyone help!
Toyota Nation Rocks!