Hissing sound vaccum leak?!?!?

[03whiteTahoeZ71]

So i recently installed a catch can to my 03 Tahoe 5.3 and ever since i been gettibg this sound. I have no leak in my hose brand new by the way installed a new PCV valve and grommet and noise still there any input wat can cause it from sounding like this.

 

[Tonyrodz]

How's the pcv rubber grommet in the valve cover? Might be a little stretched, fatigued or loose causing the vacuum sound.

 

[03whiteTahoeZ71]

The grommet is new i replaced it the day i installed the catch can hoping it will stop the sound but no luck. I installed the grommet without taking the valve cover off

 

[Tonyrodz]

I hear vacuum with mine too, or did. I don't even notice it anymore. I'm just saying it might be somewhat normal to hear something.

 

[03whiteTahoeZ71]

If it helps any i didnt put any sealent on thr catch parts and if i pinch the hose the noise stop

 

[Tonyrodz]

If it helps any i didnt put any sealent on thr catch parts and if i pinch the hose the noise stop

Neither did I. If you pinch the hose, you're obviously stopping the vacuum, so it isn't working.

 

[03whiteTahoeZ71]

I guess its jux something i have to get use too

 

[afpj]

What are your fuel trims? If LTFT is normal (not high positive at idle) then you may not have a leak per se, just air flow noise.