Hi:
The safest way to check for vacuum leaks is to have the engine running and listen for hissing sounds under the hood. Make sure to stay away from the belt and anything moving. Some mechanics will spray starting fluid or carb cleaner on vacuum hoses because if there is a leak, the engine's RPM's will raise. HOWEVER, if the starting fluid or carb cleaner hit an area that is hot enough (exhaust manifold.) It will catch fire, so I don't recommend it.
As far as the EGR, it is on the intake. There will be a vacuum hose going to it and I believe it is held on by 2 bolts. Remove the bolts and valve, make sure none of the passageways are clogged with carbon, Iif so, clean) and check that the valve opens and closes with ease (it will be tight, but make sure nothing is hanging up). Clean the carbon from the EGR too. Also, you will need to clean the old gasket off and replace it. You should be able to get just a gasket at a parts store, but make sure because I don't know where you are.
Let me know what you find. If you have other questions, let me know. It's been about 20 years, but I remember what it was like in college driving a 72 Mustang Fastback with 150K on it. That was like a car with 300K today. GO PITT!
Take care,
Joe
Tuesday, February 24th, 2009 AT 4:58 PM