What Orange said. If the EGR system is failing, it is sort of expensive to fix. Are you in a state that would require you to have it, or can you delete it?
If you can delete it, I would go ahead and do that. When I was younger I spent a great deal of $$ replacing all of the EGR components because I thought it was important, and I was nervous about buying a tuner. Big mistake, I could have bought the tuner and a tune by the time I got the CEL to turn off on its own with parts replacement.
If you have a small piece of aluminum, it's not hard to make your own block plate, just make sure to put a gasket on it. The hardest part is what to do with the manifold pipe. Some people just crimp and bend the pipe and miraculously don't get exhaust leaks, but the more preferred method is to weld the hole shut.