2010 Sundeck 260. 350 MAG engine. O2 sensor D randomly has no reading, which causes alarm to go off when reading zero. New rotor, distributor cap, plugs, plug wires and replaced all 4 O2 sensors. Boat running like new, just that Post cat random ‘D’ sensor showing no value on the tech mate. Fuse? Short somewhere? Any ideas? TIA.
