Page 263 - REPOWER REFERENCE GUIDE (2020)

8.1L/496/8.2L Triple Catalyst

2. Loosen the screw securing the oxygen sensor cover to the collector, and remove the cover.

b a - Oxygen sensor cover
b - Postcatalyst oxygen sensor
c - Precatalyst oxygen sensor

a a

c
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3. Remove the oxygen sensors, as needed.
Kent‑Moore Oxygen Sensor Socket EN46577

Installation
1. Use the oxygen sensor socket tool to install the oxygen sensor. Tighten the sensor to the specified torque.
Kent‑Moore Oxygen Sensor Socket EN46577
2. Install the oxygen sensor cover so it is flush against the collector. Tighten the screw to the specified torque.

Description Nm lb‑in. lb‑ft
Oxygen sensor 50 – 37
Oxygen sensor cover screw 3.5 31 –
3. Connect the sensor to the engine harness.
Exhaust Manifold Coolant Temperature (EMCT) Sensor

Removal
! CAUTION

A hot oxygen sensor can cause burns. Do not touch the sensor without first allowing it to cool. Always allow engine
components time to reach a safe temperature before installing or servicing engine or drive components.
1. Disconnect the EMCT sensor connector from the engine harness.

90-8M0149179 eng NOVEMBER 2018 © 2019 Mercury Marine Page 7G-15