Sounds like exhaust leak after headers installed, but no sign of a leak. Any Ideas?

I picked of a set of Circuit Werks 200 Cell Headers . I know I know, They are cheap blah blah blah. The main flange (the one that bolts to the engine) was warped a 16th of an inch or 0.050 ( no surprise). This isn't a big deal for me because I have friends with milling machines... Anyway It was machine to perfectly flat. I installed the headers using new OEM gaskets to the heads and reused the gaskets between the headers and mid pipes. I also used the stock muffler setup.. The headers fit and matched up very well so no issue there (i was surprised). I now have 200 km on the headers but I've been getting that ticking exhaust leak noise. It has that sound like its coming from one of the exhaust ports rather than where the mid pipe connects (if you've had experience with leaky exhausts then you'll know what I mean) So Ive checked for leaks with a flashlight and I can't see any evidence of any leak at all. I was expecting to see a Black Carbon trail wherever the exhaust was escaping. But theres nothing. I even had the car running while I was under it feeling around and listing and still nothing. You can hear the sound when the car is under load and you are applying the gas and you can hear it on both sides. Could it just be the sound that these headers make (Ive had headers before on V8's and I know there is a change in under the hood sound but Ive never experienced this. Maybe its the shape of them and the thickness of the steel in the tubing causing it to sound this way? Its not super load but you can hear it if you drive past a building or wall for example and it really does sound like a leak... Its very strange and I was sure that I would find a leak when I got in under the car but I cannot. Any Ideas? Could it be Valve noise? Timing chain noise? Im kind of stumped.

Its way too coincidental to be an issue with the motor at the same time you put those headers on. Whenever troubleshooting something like this, you start with what changed and work backward. I would do two things before getting concerned: 1) Get a spray bottle and put a bunch of soapy water in there. Spray allll over the exhaust . If there is a leak you will see bubbles form. 2) If that doesn't diagnose the leak, I'd go back to the stock headers before getting concerned and verify that the noise is still there (or not) before continuing down any other paths. One other question - do you have an aftermarket exhaust ? Is it possible that something is stressed or got changed due to fitment or the installation? I had an exhaust from a company that will go un-named, and the flex joint failed. I couldn't see it / find it and only when I pulled the exhaust and swapped it did I diagnose the issue. G/L, Mark

what about the washer between the Cat sensors and the headers ? Make sure those are there and are tight.

I'm using the oem exhaust and all poem gaskets.. I will try soapy water. also I checked again today and no sign of a leak at all and I have 400km on the new headers .. Retorqued nuts too.. very strange

yeah rechecked all that today.. I have a very bright led light that i checked all the welds with too.. Im very handy mechanically and do all my own work. Ive installed headers before but this is very strange

I have the same issue after I installed my fvd headers and exhaust . and solutions found?

I was looking at the Circuit Werks headers to pair with the PSE on my RS 60 Spyder - 05-08 Porsche Cayman & Boxster 987.1 Headers High Flow Catted Exhaust Haven't seen a lot of threads on this except this one that calls out issues with fitment. Any updates on how it's holding up, was the exhaust leak issue resolved? Any others that have installed this, had no issues, and enjoy the sound?

So.. I still have the sound.. I've even taken the headers off and reinstalled the OEM headers with the cats removed (smashed out of them) and guess what? I have the sound... I actually think it's the sould of the exhaust note, coupled with the fact that the headers are 6 inches off the ground and facing down. I even went as far as filling the headers with paper towel, lighting It on fire and caping off the ends.. there was no smoke escaping and no leak... Also I would like to add that I have long tube headers now.. so I've had the same sound with OEM (catless), circuit weeks and the long tubes.. I'm no longer concerned about the matter.