DTC P1451: Barometric Pressure Sensor Performance Problem
WARNING: This page is about a different car, the 1997 Suzuki Esteem. However, it is still accessible from the selected car via links, so may be relevant.
Connect scan tool to Data Link Connector (DLC). Turn ignition on. Select DATA LIST mode on scan tool. Observe manifold absolute pressure. If reading is about 100 kPa at sea level, replace PCM. Retest system. If reading is not as specified, check MAP sensor following procedures in DTC P0106 .