1998 MITSUBISHI MONTERO Service Manual

Page 537 of 1501

MITSUBISHI MONTERO 1998  Service Manual converter with the exception of the catalyst. See Fig. 5. The TWC
converter uses rhodium, with or without platinum, as its catalyst.
Rhodium helps reduce NOx emissions, as well as HC and CO.

Page 538 of 1501

MITSUBISHI MONTERO 1998  Service Manual          Single Diaphragm EGR Valve
         This type uses a single diaphragm connected to the valve by a
shaft. Diaphragm is spring-loaded to keep valve closed in the absence
of vacuum. As throttle

Page 539 of 1501

MITSUBISHI MONTERO 1998  Service Manual          Verify EGR valve is present and not modified or purposely
damaged. Ensure thermal vacuum switches, pressure transducers, speed
switches, etc., (if applicable) are not by-passed or modified. E

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MITSUBISHI MONTERO 1998  Service Manual switches, etc., (if applicable) are not by-passed or modified. Ensure
vacuum hose(s) to EGR valve is not plugged.
Fig. 9:  Typical Positive Backpressure EGR Valve
Courtesy of General Motors Corp.

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MITSUBISHI MONTERO 1998  Service Manual Fig. 10:  Typical Negative Backpressure EGR Valve
Courtesy of General Motors Corp.
         Digital EGR Valve
         The digital EGR valve operates independently of engine
manifold vacuum. This valv

Page 542 of 1501

MITSUBISHI MONTERO 1998  Service Manual These 3 orifices are opened and closed by electric solenoids. The
solenoids are, in turn, controlled by the Electronic Control Module
(ECM). When a solenoid is energized, the armature with attached sh

Page 543 of 1501

MITSUBISHI MONTERO 1998  Service Manual remote vacuum regulator. The internal solenoid is normally open, which
causes the vacuum signal to be vented off to the atmosphere when EGR
is not controlled by the Electronic Control Module (ECM). Th

Page 544 of 1501

MITSUBISHI MONTERO 1998  Service Manual          Spark control systems are designed to ensure the air/fuel
mixture is ignited at the best possible moment to provide optimum
efficiency and power and cleaner emissions.
         Ensure vacuum