I've been seeing intermittent issues with my fuel and oil pressure sensors on the 5500.
Sometimes when the engine is cold, the pressures will read way high (like 45psi fuel,
110 psi oil). Usually they return to normal when the engine gets warm(but not always).
When the engine is shut down, the pressures do not return to zero. I've tried re-setting
the zero point in the calibration page, but then I might see large negative pressures
on other days. Do I need to replace the sensors?