Restricted Exhaust System Check

1. Was the "On-Board Diagnostic (OBD) System Check" performed?

[YES] Go to Step 2.
[NO] Go to OBD System Check. Initial Inspection

2. a. Remove the Heated Oxygen Sensor (HO2S) 2.
b. Install the Exhaust Backpressure Tester in place of the Bank 1 HO2S.
c. Idle the engine at normal operating temperature. Does the reading on the gauge exceed the specified value?

[VALUES] 8.62 kPa (1.25 psi).

[YES] Go to Step 5.
[NO] Go to Step 3.

3. a. With the exhaust back-pressure tester in place of HO2S, and the engine at normal operating temperature:
- Increase the engine speed to 2000 RPM while observing the gauge.
b. Does the reading exceed the amount of the value column?

[VALUES] 8.62 kPa (1.25 psi).

[YES] Go to Step 5.
[NO] Go to Step 4.

4. a. Re-install the HO2S 2.
b. Remove the HO2S 1.
c. Install the Exhaust Back-Pressure Tester BT8515V or equivalent in place of the HO2S 1.
d. Bring the engine to normal operating temperature while observing the gauge.
e. Increase the engine speed to 2000 RPM (allow 10 seconds for pressure build) and observe the gauge.
f. Did the reading exceed the specified value?

[VALUES] 8.62 kPa (1.25 psi).

[YES] Go to Step 6.
[NO] System OK.

5. a. Repair a restriction in the exhaust system after the catalytic converter.
b. Possible faults include:
- Collapsed pipe.
- Internal muffler failure.

[YES] Verify repair.

6. Replace the restricted catalytic converter.

[YES] Verify repair.

NOTE: DTCs will be set by running the vehicle to normal operating temperature after a cold start with the Oxygen (O2) sensor disconnected. After performing these tests, use the scan tool to erase the DTCs that were set by the lack of O2 sensor activity.