[Perfectlap]

Wondering if anyone is familiar with ths sound.
When I have the car a low gear and I lift off the throttle I hear a ruffling sound coming from the pasener side of the engine. The minute I get back on the gas I can't hear it anymore or maybe the engine covers it up.
The sound is familiar to blowing on a sheet of paper along the edge.
There' also a hissing sound but it doesn't seem to be coming from the same area. But also audible when the car is going slow.
Bad MAF or 02 sensors? gulp...I hope that's all it is...