As the S2000 takes a sigh of relief and re-enters hibernation mode

I have a trusted mechanic that does work for free, even engine swaps.

Oh wait, that's me.

Hi all,

I've been chasing this sound for months and it has been driving me crazy.
Here is a clip of the sound, I removed the center console/dash to get a clear sound for the video. At the end of the video you can hear me take my foot off the throttle and the sound completely stops.

Exhaust leak? 2002 4Runner 5VZ-FE. Took out center console to hear it better. Sound only under load - YouTube

I've searched nearly every forum/ YouTube video relating to this sound I and I can't seem to find anyone with the same sound/ issue. My issue I have is a raspy/rough sound upon accelerating only. No check engine light and no noticeable issues while driving, only the sound. The noise is not there when I am in park/neutral and rev the engine. My first thought was exhaust leak, I took it to my local shop, had 2 leaks fixed and the sound is the same. Since then I have replaced the following. Fuel Filter, MAF, O2 sensor, oil and filter and air filter (spark plugs have less than 10k mi with coil packs replaces at the same time). I have also ran a few tanks of gas with fuel injector cleaner and sea foam in the gas tank as well as seafoam in crank case and the upper engine spray. I have also ran a few tanks of 91 Octane so I know its not pinging or detonation. So far nothing I have done has affected the sound, however the truck does feel smoother and more responsive since I began this process.

At this point I'm leaning towards potential vacuum leak somewhere? Or possibly exhaust leak in the crossover pipe that the muffler shop missed? (I doubt this is the case as the muffler shop is reputable)
Any help would be greatly appreciated

I would lean towards an exhaust leak. Kinda sounds like it and the fact it stops immediately when off the throttle is a big clue. A vacuum leak that severe to cause a noise would most certainly trip a code, and if it was internal it wouldn't stop when you're coasting/idling. I would take a smoke/fog machine, stick it up the tailpipe and seal around it with a bunch of rags - should be pretty easy to spot at that point.

That is the thing that has me stumped, I just recently had 2 exhaust leaks repaired, one on the driver side manifold and another one right before the first cat. I assumed the noise would have been fixed after getting it inspected at the muffler shop and having 2 leaks repaired but the sound remains almost unchanged.

I guess I could take it to another shop to get another opinion specifically on the cross pipe because I don't have a smoke machine. I'm hoping it is not the cross pipe as I know those are a PITA to deal with.

Does it sound like a concerning sound? Or should I just crank up the radio

I personally would investigate it, at least until I know exactly what's causing it, but that's just me. Some people dont care unless its causing an issue, which its evidently not in this case (or at least none that you're aware of). To determine if it's an exhaust leak you can also block off the tailpipe momentarily to hear if it gets any louder - or better yet have somebody do it for you while you look around for exhaust escaping from anywhere. Similarly you can put all four wheels on jacks and have someone hit the throttle while you poke around underneath the car to locate roughly where it's coming from.

I put a shop Vac hose in the tail pipe and covered it with a towel to create a better seal (I did not completely seal it). With the hose on I sprayed the entire exhaust with soapy water and did not see any visible leaks.

My next question is could this noise be the beginning of catalytic converter failing/ baffle coming apart? I know its not the heat shield as I have hit it with a mallet and nothing rattles.