Hey All! We have a 2002 Mits Montero Sport XLS 3.5L - A few months ago, when I'd accelerate it would make a hissing sound (which I don't feel is the right word exactly) but not a solid, steady sound....the only thing I could liken it to is a rattlesnake rattle. It has progressively gotten to where it does it without the stuttering, just a solid, steady loud noise, and it's gotten louder. It's on the passenger side under in the foot area (but the sound is coming from outside). I found a cracked hose (see picture) that's coming out of the back of the engine compartment, where I think maybe the heater system is? But I'm not sure if that would do it - although clearly that needs to be fixed lol. It's the hose that goes down, underneath the vehicle and isn't attached to anything on the other side. It's been suggested multiple times that it is some sort of vacuum leak. Any thoughts and ideas would be great!

We do have ALL the codes that come up when we run it for codes - but it always has codes come up for like the last 15 years. P0300, P0161, P0421, P0133