What is his EP pressure reading at 3800 RPM with the engine over 70 degrees C/158 F? More than 244 kPA/35 PSI indicates a restriction. DPF readings should be 0 PSI/0.45 volts KOEO; .21 PSI/0.57 volts at idle; .66 PSI/0.85 volts at 48 km/h; and 1.18 PSI/1.16 vo... Login to read more.