"Air Pressure after Filter" on Man instrument readout

Air filter restriction. Better number; 0.

If it reads -1 not running, just needs re-calibration.
0 when not running, dirty or over oiled air filter.

When running under load, you may see -1 or -2, this is normal.
You have to have a lil low pressure for the CCV to draw correctly.

Think info only and does not affect engine operation.

On MAN's they generally run higher at cruise, depening on the engine. On the 1100 common rails, generally run 4-6 at cruise. I ran a set of 820 mans that were at 20, but someone recently painted the engines and I believe they got a bunch of overspray on the air filters. Best to get the numbers on your boat at cruise with clean filters as a baseline as hull vents can be restrictive and cause those numbers to be higher than normal but no fix for that.

All is good.