Vacuum leak noise on deceleration

[Reed18b]

About a month ago I started getting a squealing noise on deceleration (sounds like a vacuum leak). I have not found any vacuum leaks, no codes being thrown. Jeep runs fine, just drives me crazy hearing the noise. Noise goes away as soon as I touch the accelerator. Any ideas?

 

[Cotril]

What side of the motor. Mine was drivers side. Turned out to be the hose that goes to the brake booster.

 

[TJ Hunnicutt]

Does it make any difference if you throw it into neutral/push in the clutch while decelerating? Trying to differentiate between driveline noises and engine noises.