Would the Egr Tube/Hose that goes into the manifold make a ticking noise if it was cracked or loose? Do you have to undo motor mount (s) and lift engine up to get access to it?
An exhaust leak can sound like a tick so its possible that is the case with the EGR tube. May want to check n your exhaust manifold/header gasket to be sure it isn't damaged. Not sure about how to get the EGR tube off. There are some people on here that have done headers, they should be able to tell you how to get it removed.