For 1990-2009 cars

(1) | HO2S 1 Exhaust Manifold Fitting
(2) | Exhaust Manifold Heat Shield
(3) | J 35314 Exhaust Back Pressure Tester

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 |

1. Remove the HO2S 1 from the exhaust manifold.
2. Install the J 35314-A exhaust back pressure tester or an equivalent in the exhaust manifold HO2S 1 fitting.

Is the action complete?

--

Go to Step 3

--

3 | Important: Place the transmission in Park or Neutral when checking exhaust system backpressure. Accurate backpressure readings can not be obtained unless the vehicle remains in Park or Neutral for all tests.

1. Start the engine.
2. Observe the exhaust system back pressure reading on the gauge with the engine idling in Park or Neutral. The gauge reading should not exceed the specified value.

Did the gauge reading exceed the specified value?

8.6 kPa (1.25 psi)

Go to Step 5

Go to Step 4

4 |

1. Increase the engine speed to 2500 RPM.
2. Observe the back pressure reading on the gauge. The gauge reading should not exceed the specified value.

Did the gauge reading exceed the specified value?

8.6 kPa (1.25 psi)

Go to Step 5

Go to Step 7

5 |

1. Check the entire exhaust system for a collapsed pipe, heat distress, or possible internal muffler failure.
2. Replace any faulty components.

Did any component require replacement?

--

Go to Step 7

Go to Step 6

6 | Replace the catalytic converter. Refer to Front Pipe Replacement in Engine Exhaust. Is the action complete? | -- | Go to Step 7 | --
7 |

1. Idle the engine until normal operating temperature is reached.
2. Check for DTCs.

Are any DTCs displayed that have not been diagnosed?

--

Go to the applicable DTC table

System OK