Isuzu 2008MY N Series Workshop Manual page 357

1A-354 Engine Control System (4HK1)
Checks
Exhaust System Checks
Additional Checks
Inspect the exhaust system for a possible restriction. Refer to Exhaust System
in Section 1G Engine Exhaust.
• Electromagnetic interference (EMI) on the reference circuit can cause an
engine miss condition. The scan tool can usually detect EMI by monitoring
the engine speed. A sudden increase in speed with little change in actual
engine speed change indicates that EMI is present. If a problem exists,
check routing of high voltage components, such as fuel injector solenoid
valve wiring, near the sensor circuits.
Action