On the 1998 Mazda B2500, the P1401 is a fairly straight forward code pointing to a fault with the Pressure Feedback Exhaust Sensor (aka EGR Position Sensor). It’s actually a fairly common fail item on these vehicles. Carefully inspect the rubber lines at the base of the sensor and the metal tubes they connect to, looking for any cracks, holes or loose/missing connections (inspect carefully! very common for these to dry-rot and crack!). Inspect the electrical connector and wire harness for any loose, broken or damaged wires. If the visual inspection checks ok, replace the DPFE Sensor. It’s located on the top, rear, passenger’s side of the engine.
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