Page 257 - REPOWER REFERENCE GUIDE (2020)

8.1L/496/8.2L Triple Catalyst
6. Remove the exhaust elbow riser.

c
a - Exhaust collector
b b - Gasket
c - Screw (6)
a d - Exhaust elbow riser

d

48943
Collector 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.
NOTICE

Exposing the catalyst to foreign materials such as silicone, oils, or fiberglass can chemically alter the precious metal coating
of the catalyst and compromise its ability to convert exhaust gases. Handle catalyst components in a clean environment only.

1. Remove the exhaust elbow/riser as described in Riser Removal.
IMPORTANT: Some water may remain in the exhaust manifold. Drain the exhaust elbows prior to removing the
components.
2. Drain any remaining water from the exhaust collector and exhaust elbow/riser.
3. Disconnect the temperature sensor and the two oxygen sensors from the engine harness.
4. Disconnect the cooling water inlet hose from the aft end of the collector.
5. Remove the 10 screws securing the collector to the manifold.
IMPORTANT: The catalyst retaining rings use friction to keep the catalyst in the collector during installation and removal.
Over time, the clamping force of these rings may weaken, causing the catalysts to fall from the collector during assembly
or disassembly. Take care not to drop the catalysts and replace the retaining rings before installation.

90-8M0149179 eng NOVEMBER 2018 © 2019 Mercury Marine Page 7G-9