EGR Orifice in Intake Manifold May Plug With Sludge and Cause Misfire on Mercury Monterey

Submitted by Vehicle Owner · May 29, 2025
Published by RepairPal

Problem overview

On higher mileage vehicles, one or more EGR orifice in the intake manifold may plug with sludge. This can cause the engine to misfire when first accelerating because too much exhaust gas is directed into the cylinders where the orifice is not plugged. Cleaning the clogged passages should correct this concern.

20 people reported this problem
6 comments
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Mercury Monterey vehicles with this problem

Average mileage: 125,357 miles
(72,000 - 258,000)

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