6E±589
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Vehicle surges during cruise.
Rough idle.
DTC P0300 (misfire detected).
Too little or no EGR flow may allow combustion
temperatures to get too high. This could cause:
Spark knock (detonation).
Engine overheating.
Emission test failure.
DTC P0401 (EGR flow test).
Poor fuel economy.
0017
EGR Pintle Position Sensor
The PCM monitors the EGR valve pintle position input to
endure that the valve responds properly to commands
from the PCM and to detect a fault if the pintle position
sensor and control circuits are open or shorted. If the
PCM detects a pintle position signal voltage outside the
normal range of the pintle position sensor, or a signal
voltage that is not within a tolerance considered
acceptable for proper EGR system operation, the PCM
will set DTC P1406.
General Description (Positive
Crankcase Ventilation (PCV) System)
Crankcase Ventilation System Purpose
The crankcase ventilation system is use to consume
crankcase vapors in the combustion process instead of
venting them to the atmosphere. Fresh air from the
throttle body is supplied to the crankcase and mixed with
blow-by gases. This mixture is then passed through the
positive crankcase ventilation (PCV) valve into the
common chamber.
Crankcase Ventilation System Operation
The primary control is through the positive crankcase
ventilation (PCV) valve. The PCV valve meters the flow at
a rate that depends on the intake vacuum. The PCV valve
restricts the flow when the inlet vacuum is highest. Inaddition, the PCV valve can seal the common chamber
off in case of sudden high pressure in the crankcase.
028RV002While the engine is running, exhaust fuses and small
amounts of the fuel/air mixture escape past the piston
rings and enter the crankcase. These gases are mixed
with clean air entering through a tube from the air intake
duct.
060R200063During normal, part-throttle operation, the system is
designed to allow crankcase gases to flow through the
PCV valve into the throttle body to be consumed by
normal combustion.
6F±2ENGINE EXHAUST (6VE1 3.5L)
General Description
150RW023
When inspecting or replacing exhaust system
components, make sure there is adequate clearance
from all points on the underbody to prevent overheating
the floor pan and possible damage to the passenger
compartment insulation and trim materials.
Check complete exhaust system and nearby body areas
and rear compartment lid for broken, damaged, missing
or mispositioned parts, open seams, holes, loose
connections or other deterioration which could permit
exhaust fumes to seep into the rear compartment or
passenger compartment. Dust or water in the rear
compartment may be an indication of a problem in one of
these areas. Any faulty areas should be corrected
immediately.
Hangers
Various types of hangers are used to support exhaust
system(s). These include conventional rubber straps,
rubber rings, and rubber blocks.
The installation of exhaust system supports is very
important, as improperly installed supports can cause
annoying vibrations which can be difficult to diagnose.
Three Way Catalytic Converter
The three way catalytic converter is an emission control
device added to the exhaust system to reduce pollutants
from the exhaust gas stream.
CAUTION: The catalytic converter requires the use
of unleaded fuel only.
Periodic maintenance of the exhaust system is not
required. If the vehicle is raised for other service, it is
advisable to check the condition of the complete exhaust
system.
A dual bed monolith catalytic converter is used in
combination with three way catalytic converter.
Catalytic Converter Types:
Three way (Reduction/Oxidation) catalyst
The catalyst coating on the three way (reduction)
converter contains platinum and rhodium which lowers
the levels of nitrous oxide (NOx) as well as hydrocarbons
(HC) and carbon monoxide (Co).
Gasket
The gasket must be replaced whenever a new exhaust
pipe, muffler or catalytic converter is installed.
