Isuzu 1999 RODEO Workshop Manual page 995

6E1–368 RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
EXCESSIVE EXHAUST EMISSIONS OR
ODORS SYMPTOM
DEFINITION:
Vehicle fails an emission test. There is excessive "rotten
egg" smell. (Excessive odors do not necessarily indicate
excessive emissions.)
Step
1 Was the On–Board Diagnostic (OBD) System Check
performed?
2 1. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
3 Was visual/physical check performed?
4 Check for vacuum leaks (vacuum lines, intake
manifold, throttle body, etc.)
Were any vacuum leaks found?
5 1. Check fuel cap for proper installation.
2. Secure the fuel cap if necessary.
Was a problem found?
6 1. Check the fuel pressure. Refer to Fuel System
Pressure Test.
Was a problem found?
7 1. Check for faulty, plugged or incorrectly installed
PCV valve.
2. Verify that the PCV system is not plugged.
Was a problem found?
8 Check the injector connections. If any of the injectors
are connected to an incorrect cylinder, correct as
necessary.
Was a problem found?
9 Perform the Injector Coil/Balance Test.
Was a problem found?
10 Check for a problem with the engine cooling system.
Was a problem found?
11 Check the EVAP canister for fuel loading. Refer to
Evaporative Emission Control System.
Was a problem found?
12 1. Remove excessive carbon build-up with a top
engine cleaner. Refer to the instructions on the top
engine cleaner can.
2. Perform the exhaust emission test.
Does the vehicle pass the test?
13 Perform the exhaust emission test.
Does the vehicle pass the test?
14 Does the exhaust emission test indicate excessive HC
levels, or is "Long Term Fuel Trim" significantly in the
negative range (rich condition)?
Action Value(s) Yes
— Go to Step 2
Go to Step 13
—
— Go to Step 4
Go to Step 13
—
Go to Step 13
—
Go to Step 13
—
Go to Step 13
—
Go to Step 13
—
Go to Step 13
—
Go to Step 13
—
Go to Step 13
—
— System OK
— System OK
Go to Step 15
—
No
Go to OBD
System
Check
Go to Step 3
Go to Visual /
Physical
Check
Go to Step 5
Go to Step 6
Go to Step 7
Go to Step 8
Go to Step 9
Go to Step 10
Go to Step 11
Go to Step 12
Go to Step 14
Go to Step 14
Go to Step 16