Excessive Exhaust Emissions or Odors. Cadillac Concours 1996

For 1990-2009 cars

#### Excessive Exhaust Odors Symptom

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
DEFINITION: Vehicle has excessive rotten egg smell. Excessive odors do not necessarily indicate excessive emissions.
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Step 2 | Go to the Powertrain (OBD) System Check

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?

--

Go to Step 18

Go to Step 3

3 | Was a thorough visual/physical check performed? | -- | Go to Step 4 | Go to Visual /Physical check

4

1. Check for vacuum leaks.Vacuum lines, EGR system, Intake manifold, Throttle body etc.
2. If a problem is found, repair as necessary.

Were any vacuum leaks located?

--

Go to Step 18

Go to Step 5

5

1. Check the fuel cap for proper installation.
2. Secure the fuel cap if necessary.

Was the fuel cap installed properly?

--

Go to Step 6

Go to Step 18

6

1. Check fuel pressure. Perform Fuel System Check.
2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 18

Go to Step 7

7

1. Check for faulty, plugged, or incorrectly installed crankcase ventilation valve; also check crankcase ventilation system for being plugged.
2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 18

Go to Step 8

8

1. Check the injector connections.
2. If any of the injector connectors are connected to an incorrect cylinder, correct as necessary.

Was a problem found?

--

Go to Step 18

Go to Step 9

9

1. Perform Injector Flow/Voltage Drop Check.
2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 18

Go to Step 10

10

1. Refer to Cooling and Radiator for cooling system diagnosis.
2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 18

Go to Step 11

11

1. Check EVAP canister for fuel loading. Refer to Powertrain Emission System.
2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 18

Go to Step 12

12 | Remove excessive carbon buildup with a top engine cleaner. Refer to instructions on top engine cleaner can. Is the exhaust odor still present? | -- | Go to Step 13 | Go to Step 18
13 | Check items that can cause the engine to run rich. Make any necessary repairs. Is the exhaust odor still present? | -- | Go to Step 14 | Go to Step 18
14 | Check items that can cause the engine to run lean. Make any necessary repairs. Is the exhaust odor still present? | -- | Go to Step 15 | Go to Step 18

15

1. Check the EGR system. Refer to EGR Diagnosis.
2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 18

Go to Step 16

16

1. Check for an engine mechanical problem. Perform a cylinder compression check. Refer to Engine Mechanical.
2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 18

Go to Step 17

17

1. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no malfunctions have been found, review/inspect the following:

• | Visual/physical inspection.

• | Scan Tool data.

• | Freeze Frame data/Failure Records Data.

• | All electrical connections within a suspected circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 18

Go to the Powertrain (OBD) System Check

18 | Operate the vehicle to duplicate conditions present when the original symptom was noted. Is symptom still present? | -- | Go to Step 3 | Repair complete.