Hi Tim, I had this on a 2010 Accord Tourer, it could be either the manifold split, they were made as two parts and welded together, they did recall them but under 60K. I had the same issue on my 2011 CRV this was replaced by Honda.
But I also had a concertina type exhaust pipe on the rear of the engine go on the Accord , that had to be replaced, about £170 for the pipe and £300 labour as the pipe is at the rear of the engine and hard to get to 😞