According to edmunds, for 2003, there is a new 2.5 Limited Edition trim, which includes GXE front fascia styling, the 165-horsepower QR25 4-cylinder engine, standard automatic transmission, standard Antilock Braking System (ABS) and side-impact supplemental airbags.
The Sentra CA model is no longer available as all 1.8-liter engine-equipped Sentra XE and GXE models sold with California emission specifications offer zero evaporative emissions and meet SULEV (Super Ultra Low Emission Vehicles) standards. Other changes this year include a new power steering ratio for XE and GXE, a revised six-speed manual transmission for SE-R Spec V model and a new bright yellow exterior paint color for the SE-R and SE-R Spec V.
Download here 2003 Nissan Sentra Owners Manual