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 HO2S 1 fitting of the exhaust manifold .

Is the action complete?

--

Go to Step 3

--

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

1. Start the engine.
2. Observe the back pressure reading on the gauge with the engine idling in Park or in 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 exhaust system for a collapsed pipe, for any heat stress, and for an 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 there any DTCs that have not been diagnosed?

--

Go to the applicable DTC table

System OK