Saab 2000 9-5 - Manual (Page 133)

133 Starting and driving
advantages of the system is that it
enables the engine to be run safely on
lower-grade fuel, although not lower
than AON 87.
• The maximum boost pressure is
adjusted automatically to the knocking
or pinging tendency of the engine.
Occasional, short-lived knocking when
the engine is under a heavy load is per-
fectly normal; the extent will depend on
the grade of fuel in the tank.
• Isolated instances of knocking are
more likely to occur with low-octane
fuel. This controlled form of knocking,
followed by a reduction in the boost
pressure, is a sign that the wastegate is
functioning and is perfectly safe for the
engine.
Important considerations with cata-
lytic converters
The catalytic converter is an emission-con-
trol device incorporated in the car’s exhaust
system. It consists of a metal canister with a
honeycomb insert, the cells of which have
walls coated in a catalytic layer (mixture of
precious metals).
NOTE
If constant knocking occurs every time a
load is put on the engine, this indicates a
malfunction in the system.
Have the car checked without delay by an
authorized Saab dealer.
WARNING
If the engine is being run with the car on a
rolling road or dynamometer, to ensure
adequate cooling, air must be blown into
the engine compartment and under the
car at a rate equivalent to the ram-air
effect that would be obtained at the corre-
sponding road speed.
NOTE
Use only unleaded gasoline. Leaded gas-
oline is detrimental to the catalyst and
oxygen sensor and will seriously impair
the function of the catalytic converter.
IB661
2
1
3
Oxygen-sensor-controlled
injection system
1 Engine control module
2 Oxygen sensor (lambda probe)
3 Catalytic converter