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DTC P0301 is cylinder 1 missfire and P0156 is Oxygen sensor 2 bank 2 circuit. The P0301 is most likely a spark plug wire, coil or fouled plug. The engine in your Windstar also has problems with the intake manifold gaskets causing a vacuum leak. This usually give lean codes but it may also give the cylinder missfire. The P0156 is most likely caused by a oxygen sensor but a scan tool will be needed to monitor the sensor readings.