O2 Sensor Wire
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 1993 Pontiac Bonneville, 1993 Oldsmobile Ninety-Eight, 1993 Oldsmobile Eighty-Eight, 1993 Buick Riviera, and 1993 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
O2 sensor wire may be mispositioned and laying against exhaust manifold. Check for ground between sensor and wire connector.