Catch cans are useless, and you might hear a change in vacuum sound, but not as you describe.

 

yes but I am not getting any codes and if it’s the catch can then why it only happen when the car on cold start not every single start

 

not like I described and surprisingly the catch can caught some oil before it dump it to my intake I like it it keeps my intake clean

maybe I’ll see if I can like record a video and post it so you can hear the sound. I’ll do that after work today

 

try retorquing your intake manifold bolts then. that can cause a hot / cold issue. gaskets can shrink in the cold

 

Here is a video I uploaded
see how you hear like dee dee dee Dee for few seconds then it go back to normal

 

I can hear a worn pulley bearing.

 

really? Pulley bearing? Like the idler pulley?
you didn’t hear back from the exhaust or front where it like does dee dee Dee I swear I can hear it it’s not normal . Maybe I will take another video to see if I can get a clearer sound

if you listen like after 15 secs in you will hear it

 

Here is another video that’s clearer
if you folks can hear it and help me out would be great

 

Yes, there is an uneven running sound. Check compression, relative compression and clean your maf. Just a thought as a starting point. Clean TB. Tighten intake manifold bolts.

 

yes it only happen when the engine is cold like first start. If I go somewhere and turn it off and back on it’s normal . It just first start when it’s fully cold it does that for like 10 secs 20 secs then it goes back to normal. I already cleaned the maf but I’ll clean it again and do the other tests and report back