Diagnostic Procedure 2 — Hunting
EF & EC-429flowchartEXHAUST GAS SENSOR check applies to MODELS WITH CATALYZER ONLY.
Diagnostic Procedure 2 — Hunting
1
CHECK EXHAUST GAS SENSOR. (MODELS WITH CATALYZER ONLY) When disconnecting exhaust gas sensor harness connector, is the hunting fixed?
Yes
Check exhaust gas sensor. (See page EF & EC-494.)
No
2
PERFORM POWER BALANCE TEST. 1. Perform "POWER BALANCE" in "ACTIVE TEST" mode. 2. Is there any cylinder which does not produce a momentary engine speed drop? — OR — When disconnecting each injector harness connector one at a time, is there any cylinder which does not produce a momentary engine speed drop?
No
Go to 4
Yes
3
CHECK SPARK PLUGS. Remove the spark plugs and check for fouling, etc.
N.G.
Repair or replace spark plug(s).
O.K.
4
(Go to A on next page.)