Headers Leak?

I recently intalled OBX headers in my Integra. I have been noticing a "ticking" sound when accelerating from a stop or even while accelerating at highway speeds. I have checked the bolts and everything is tight. Any thoughts?

If it were leaking, you would hear a noticeable change in the exhaust tone and it would get louder. Typically this happens when you don't use new gaskets when installing the new header. However a ticking doesn't really sound like it would be an exhaust leak. Can you isolate the noise's origin? Does it only happen under acceleration? What about if you have the car in park or neutral but give it gas?