EXHAUST PRESSURE FITTING
The exhaust pressure fitting is threaded into the adapter housing and protrudes into the inner exhaust.

- Exhaust pressure fitting
A hose is routed from this fitting to the EMM. Due to carbon accumulation in the exhaust, this fitting must be periodically de-carbonized or replaced.
Operation Test
Use the Evinrude Diagnostics software Monitor screen to confirm:
- barometric pressure reading; and
- changes in exhaust pressure reading.
With key ON, outboard NOT running, make sure the barometric pressure reading reflects actual atmospheric conditions.
If barometric pressure reading is inaccurate, remove exhaust/barometric pressure hose from EMM. Retest and observe engine Monitor screen. If barometric pressure reading is accurate with hose removed, replace hose and diaphragm assembly. and inspect exhaust fitting for restriction.
With key ON, outboard NOT running, the exhaust pressure sensor reading should be close to zero. With the outboard running, make sure the exhaust pressure reading changes with throttle setting. This reading will vary, based on actual outboard exhaust pressure conditions.
If the exhaust pressure readings are not as described, clean or replace exhaust pressure fit tings.

Engine Monitor Screen
- Barometric pressure reading
- Exhaust pressure reading
Cleaning
Cleaning with Engine Tuner maintenance product can dissolve carbon build-up.
Spray Engine Tuner through the fitting and allow it to soak for four to six hours.
Wear safety glasses to avoid personal injury, and set compressed air pressure to less than 25 psi (172 kPa).
Use compressed air to blow through the fitting. Limit the air pressure to 25 psi (170 kPa). Confirm movement of air through fitting.
IMPORTANT: Fitting does restrict air movement.
Replace exhaust pressure fittings that are blocked and cannot be decarbonized.
