I see you still have the original style Larini where the end pipes are connected with a clamp to the muffler.
They will often get loose and cause the exhaust tips to sag and leak.
So I would do three things:
1. Check and make sure that the Cat pipe doesn't have a crack at the U-bend. That will cause an exhaust leak but typically will also throw a CEL
2. get the tips welded to the muffler and get rid of those clamps.
3. Get rid of those flimsy exhaust clamps and get something that you won't have to re-tighten all the time. I use these:
Edelstahl Auspuff Schelle 66,5 Klemmbereich Ø 65 - 68mm | eBay
Not sure if they ship to the US, but they are very sturdy clamps and I never had to tighten them again after I installed those. The ones I had before (like the ones you have) came loose all the time.