If the code is still a lean code, and its the only one you have, you might look in to your injector o-rings being replaced. This can be done in about 35 minutes, even though it seems like its really complicated.
There is a very detailed write up under the duratec maintenance forum, in the stickied FAQ (under "UIM/LIM rebuild"
I suggest doing a UIM/LIM rebuild with that many miles to restore power (you've lost more than you think....), gas mileage, efficiency, and to eliminate that code.
Ray