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Home >> Chevrolet >> 2008 >> Optra LS, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - 1.6L >> Diagnostic Information and Procedures >> DTC P0300-P0304 >> Circuit/System Verification
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Circuit/System Verification

  1. Engine running at the normal operating temperature. Verify there is no abnormal engine noise.
  2. Observe the DTC information with a scan tool. DTCs P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0335, P0336, P0337, P0351, or P0352 should not set.
    3. IMPORTANT: A misfire may only occur when the engine is under load. An engine load may be necessary to verify the condition.
  3. Engine running, disconnect one fuel injector connector at a time to isolate the misfiring cylinder. The engine speed should change when an injector is disconnected.
  4. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
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