O2 Sensor Wire
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 1994 GMC Vandura, 1994 GMC Rally, 1994 GMC Pickup, 1994 Chevrolet Sportvan, and 1994 Chevrolet Pickup. However, it is still accessible from the selected car via links, so may be relevant.
Wire may be mispositioned and touching exhaust manifold. Check for ground between sensor and wire connector.