OBD II enhanced emission standards
require the engine control module
(ECM) to monitor the oxygen content in
the exhaust both before and after the
catalytic converter. This allows for
tighter control of the tail pipe emissions
and also allows the ECM to diagnose
converter problems. If the ECM detects
that catalytic converter or oxygen
sensor efficiency has degraded past a
certain pre-programmed limit, it will
turn on the Check Engine light, and
store a diagnostic trouble code (DTC)
in the ECM. See
OBD On Board
Diagnostics
in the rear of this manual
for more information on OBD systems.
Replacement of oxygen sensors at the
specified intervals ensures that the
engine and emission control system
will continue to operate as designed.
Extending the replacement interval
may void the emission control warranty
coverage. See
180 Exhaust System
for information on replacing the oxygen
sensors.
Tightening torque
Oxygen sensor to
exhaust manifold
50 Nm (37 ft-lb)
Note:
A special socket for replacing the
oxygen sensor is available from most
automotive parts stores. The socket
has a groove cut down one side to allow
the sensor to be installed without
damaging the wire harness.
Power steering fluid, checking
level
To check power steering fluid level in
fluid reservoir:
Maintenance
http://ebahn.bentleypublishers.com/BMW/3/E46/Repair%20Manuals/0...
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Summary of Contents for 1999-2005 M3
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