Isuzu 2000 Trooper Workshop Manual page 1193

6E–324
TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
7. Difficulty completing the DTC P0420 "Status This
Ign." test may be encountered in areas where test
conditions cannot be maintained easily, especially in
urban areas. To minimize the amount of driving
required to complete the DTC P0420 "Status This
Ign." test, use the following procedure:
D Allow the engine to warm completely.
D With the vehicle in "Park," monitor mass air flow on
the Tech 2 and hold part throttle to maintain a
reading of over 12 g/second for at least 2 minutes.
This will achieve the "warm catalyst" required for
running the test.
D Operate the vehicle in second or third gear to remain
in the DTC P0420 test conditions described in
"Conditions for Setting the DTC" as much as
possible. If you must stop the vehicle, maintain the
"warm catalyst" criteria as follows:
– Place the vehicle in "Park" or "Neutral."
– Hold part throttle to maintain a mass air flow
reading of over 15 g/second for the duration of the
stop.