Possible exhaust leak after headers? Attached data log

[Fairlight]

Hey guys I installed Grupple-S UEL headers and used OFT to tune my car to stage 2 plus. I notice sometimes when I let off the throttle I can hear a whizzing sound (kinda sounds like a BOV but a lot quieter) underneath the car. Its actually pretty rare that I hear this noise but it does sometimes randomly pop up. I've heard that I'm supposed to hear these noises now because the metal on the aftermarket headers is thinner than the OEM header?

Just want to make sure I don't have an exhaust leak. I did a data log of me driving for 5 minutes:

https://datazap.me/u/lol123/log-1618...0&data=1-10-11

Thanks in advance!

[tomm.brz]

No leaks
Car is noisier with lightweight uncatted header, tune seems good

[Plumbus]

The only way to know with 100% certainty is to get under the car and spray soapy water on the flanges with a shop vac blowing from the back. Or you could make/buy a cheap smoke machine IF you have a compressor handy and check the same way. I thought I might have a leak but it turns out it was the ceramic coating getting baked by the exhaust heat, causing the smell. also there is a sound like rushing water but only when on mid to heavy acceleration, and it's cuz the steel is thinner than OEM plus no heatshield, and the rushing air can be heard much easier.

I wonder if people with wrapped headers can hear the rushing sound?

[Lantanafrs2]

I just resign to the idea of snugging the fasteners once in a while