+1 on above.
Do you want to fix this yourself? If so, always post the full DTC codes. There are 1000's and they each have a story to tell.
In general, a lean DTC is usually a vacuum leak, exhaust leak, dirty MAF, or clogged fuel injector.
If you are POSITIVE there aren't any vacuum leaks/exhaust leaks, then consider an injector cleaning/flow test service such as injectorRX.com. Once cleaned and tested they are as good as new. Cheaper than new.
I can also help you get a full copy of the Ford service manual. PM if interested.
2003 GT Convertible (sold)
2000 GT coupe (fix up project)