P430

New 02/05/2005

Checked a car today with the famous NGS and got a P430 - 2nd CAT out of range. The symptoms were spontaneous sputtering, having to work the go pedal to keep it running and then would just go away.
Now the interesting thing is that the code didn't throw the CE light which meant it was pending waiting for another cycle occurrence.

Don't have the answer yet but here is what we have found out so far.

U.L.

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HF1 DTCs P0420, P0421, P0430 or P0431: CHECK FOR MISFIRE Checked a car today with the famous NGS and got a P430 - 2nd CAT out of range. The symptoms were spontaneous sputtering, having to work the go pedal to keep it running and then would just go away.

Now the interesting thing is that the code didn't throw the CE light which meant it was pending waiting for another cycle occurance.

Don't have the answer yet but here is what we have found out so far. Checked a car today with the famous NGS and got a P430 - 2nd CAT out of range. The symptoms were spontaneous sputtering, having to work the go pedal to keep it running and then would just go away.

Now the interesting thing is that the code didn't throw the CE light which meant it was pending waiting for another cycle occurance.

Don't have the answer yet but here is what we have found out so far.DETECTION MONITOR DTCS

Diagnostic Trouble Codes (DTC) P0420 and P0421 indicate that bank 1 catalyst system efficiency is below the acceptable threshold.

Diagnostic Trouble Codes (DTC) P0430 and P0431 indicate that bank 2 catalyst system efficiency is below the acceptable threshold.

NOTE 1: Complete the spark timing check in Quick Test before proceeding with this test step. Spark timing retarded below specification can increase exhaust gas temperature and decrease catalyst efficiency over time.

NOTE 2: Be sure customer has not:

Refueled vehicle with leaded gasoline.
Noticed high vehicle oil consumption.

NOTE 3: If entering this Pinpoint Test for symptoms only, go immediately to HF5 .

NOTE 4: Internal deterioration of a catalytic converter is usually caused by abnormal engine operation upstream of the catalyst. Events that can produce higher than normal temperatures in the catalyst are particularly suspect. For example, misfiring can cause higher than normal catalyst operating temperatures.

Possible causes:

Use of leaded fuel.
Oil contamination.
Cylinder misfiring.
Damaged HO2S.
Damaged ECT sensor.
Downstream HO2S wires improperly connected.
Fuel pressure too high.
Damaged exhaust system pipe.
Damaged exhaust manifold.
Damaged muffler/tailpipe assembly.
Damaged catalytic converter.

Key on, engine off.
Retrieve and record all Continuous Memory DTCs (MIL and non-MIL).

Were any of the following Misfire Detection Monitor DTCs recorded: P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307 and P0308?

Yes	No
GO to Section 4A, Powertrain Diagnostic Trouble Code (DTC) Charts , to address the Misfire Detection Monitor DTCs.	GO to HF2 .

HF2 CHECK FOR HO2S MONITOR DTCS

NOTE 1: Incorrect HO2S signal input (e.g. rich/lean input signal when the engine is operating under lean/rich conditions) can cause an abnormal temperature increase in the catalyst.

NOTE 2: Non-California applications will not have an active HO2S monitor. As a result, a Catalyst Efficiency Monitor DTC can be generated for a rear HO2S concern. To check for a rear HO2S concern on these applications, go to the HO2S monitor Pinpoint Test Step H81 . If any repair actions are necessary in Pinpoint Test H, run KOER Self-Test to verify the repair. If repair actions are not necessary, go to HF3 .

Were any of the following HO2S monitor DTCs recorded in HF1: P0136, P0138, P0140 and P0141 (Bank 1, rear HO2S) or P0156, P0158, P0160 and P0161 (Bank 2, rear HO2S)?

Yes	No
GO to Section 4A, Powertrain Diagnostic Trouble Code (DTC) Charts , to address the HO2S Monitor DTCs.	GO to HF3 .

HF3 CHECK FOR ECT SENSOR DTCS

Note: ECT sensor DTCs can indicate that the thermostat is not operating correctly or that the engine coolant level is not filled to specification, producing above normal operating temperatures.

Were any of the following ECT sensor DTCs recorded in HF1: P0117, P0118, P0125 and P1117?

Yes	No
GO to Section 4A, Powertrain Diagnostic Trouble Code (DTC) Charts , to address the ECT sensor DTCs.	GO to HF4 .

HF4 CHECK FOR ANY OTHER DTCS

Were any other DTCs recorded in HF1 (not including the initial P0420/P0421 or P0430/P0431 DTCs)?

Yes	No
GO to Section 4A, Powertrain Diagnostic Trouble Code (DTC) Charts , to address the DTCs.	GO to HF5 .

HF5 CHECK REAR HO2S WIRING AND PCM CONNECTIONS

Note: If the electrical connections of the rear HO2S are interchanged/crossed, the Catalyst Efficiency Monitor Test will fail.

· Inspect the wiring of each rear HO2S for proper routing and connection.

· Disconnect the PCM, inspect for damaged or pushed out pins, corrosion and loose wires.

Are there any concerns with the HO2S wiring on the PCM connection?

Yes	No
SERVICE any wiring or connection concerns. For PCM pin concerns, REPLACE PCM. RECONNECT all components. RERUN Quick Test .	No Electronic EC root causes related to the DTCs or symptoms. GO to HF6 .

HF6 CHECK FUEL PRESSURE

WARNING: THE FUEL SYSTEM WILL REMAIN PRESSURIZED WHEN THE ENGINE IS NOT RUNNING. TO PREVENT INJURY OR FIRE, USE CAUTION WHEN WORKING ON THE FUEL SYSTEM.

Note: Fuel pressures above specification can produce an abnormally rich air/fuel mixture. The rich air/fuel mixture can cause higher than normal catalyst operating temperatures.

· Key off.

· Inspect the vacuum hose going to the fuel pressure regulator for proper installation and cracks. Service as necessary.

· Install fuel pressure gauge.

· Verify vacuum source to fuel pressure regulator.

· Start and run the engine at idle. Record the fuel pressure.

· Increase engine speed to 2500 rpm and maintain for one minute. Record the fuel pressure.

Is the fuel pressure between 210-310 kPa (30 and 40 psi)?

Yes	No
Fuel pressure is OK. REMOVE the fuel pressure gauge. GO to HF7 .	Fuel pressure is out of specification. For Probe: GO to Section 5B, Pinpoint Test HC, Probe Fuel Delivery System, for diagnosis. All others: GO to Section 5A , Pinpoint Test Step HC1 , Fuel Delivery Systems, for diagnosis. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test.

HF7 CHECK FOR OBVIOUS LEAK SOURCES IN THE EXHAUST SYSTEM

Note: If a catalyst is in series with a leaking exhaust system, it can fail the Catalyst Efficiency Monitor test.

· Key off.

· Inspect the following for leaks, cracks, loose connections or punctures:

§ Exhaust manifold.

§ Front exhaust pipe.

§ Rear exhaust pipe.

§ Muffler/tailpipe assembly.

Are the above components free of cracks and punctures, etc.?

Yes	No
CHECK that the exhaust manifold to catalyst inlet pipe joint is tight. GO to HF8 .	SERVICE the leak source(s). COMPLETE PCM Reset to clear DTCs. RERUN Quick Test .

HF8 CHECK FOR OBVIOUS RESTRICTIONS IN THE EXHAUST SYSTEM

· Inspect the following for dents, areas of collapsed material and unusual bending:

§ Front exhaust pipe.

§ Rear exhaust pipe.

§ Muffler/tailpipe assembly.

Are the components free of dents and areas of collapsed material or unusual bending, etc.?

Yes	No
GO to HF9 .	SERVICE the restricted component(s) as necessary. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test .

HF9 CHECK MANIFOLD VACUUM FOR INDICATION OF EXCESSIVE EXHAUST SYSTEM RESTRICTION

· Attach a vacuum gauge to the intake manifold vacuum source.

· Install a tachometer.

· Observe the vacuum gauge needle while performing the following:

Note: The vacuum gauge reading may be normal when the engine is first started and idled. However, excessive restriction in the exhaust system will cause the vacuum gauge needle to drop to a low point even while the engine is idled.

§ Start the engine and gradually increase the rpm to 2000 with the transmission in NEUTRAL.

· Decrease engine speed to base idle rpm.

· Key off.

Did manifold vacuum rise above 54 kPa (16 inches-Hg) with the engine rpm at 2000?

Yes	No
GO to HF10 .	Manifold vacuum did not reach an acceptable level. GO to HF11 to check for excessive restriction in the exhaust system.

HF10 CHECK MANIFOLD VACUUM FOR INDICATION OF MODERATE EXHAUST SYSTEM RESTRICTION

· Vacuum gauge installed.

· Tachometer installed.

· Key on, engine idling.

· Increase the engine speed gradually from base idle rpm to 2000 rpm with the transmission in NEUTRAL.

· Observe the speed the vacuum gauge needle rises, while maintaining the increased engine rpm.

· NOTE 1: On a non-restricted exhaust system, the vacuum gauge needle will rise quickly to the normal range as the increased rpm is maintained.

· NOTE 2: On a restricted exhaust system, the vacuum gauge needle will rise slowly to the normal range as the increased rpm is maintained.

· NOTE 3: The rate of speed the vacuum gauge needle rises to the normal range is slower on a restricted system than on a non-restricted system as the increased rpm is maintained.

· Decrease engine speed to base idle rpm.

· Key off.

Is the rate of speed that the vacuum gauge needle rises back to the normal range (above 54 kPa (16 inches-Hg)) much slower than that of a non-restricted system?

Yes

A moderate restriction may be present. GO to HF11 .

No indications of restrictions or leaks have been detected in the exhaust system. If here because of DTCs P0420/P0421 or P0430/P0431, the catalytic converter is chemically inactive. REPLACE the catalytic converter. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test . REMOVE the vacuum gauge and tachometer. For further diagnosis of symptom (e.g. Lack of Power, Loss of Power, or No Start) REFER to Section 3A , Symptom Charts.

HF11 CHECK MANIFOLD VACUUM WITH EXHAUST MANIFOLD DISCONNECTED FOR INDICATION OF A RESTRICTION

Note: An intake manifold gasket leak can also cause the vacuum gauge needle to remain well below the normal range.

· Key off.

· Disconnect exhaust system immediately after the exhaust manifold.

· Repeat the vacuum measurement found in test step HF10 .

Did the vacuum needle QUICKLY rise above 54 kPa (16 inches-Hg) with the engine rpm at 2000?

Yes

The exhaust system restriction is downstream of the exhaust manifold. RECONNECT exhaust system at exhaust manifold. GO to HF12 .

A restriction is present in the exhaust manifold. REMOVE the vacuum gauge and tachometer. INSPECT each exhaust port for casting flash/restrictions by dropping a length of chain into it (NOTE: Do not use a wire or lamp to check the ports. The restriction can be small enough for both to pass through, but large enough to cause excessive back-pressure at high engine rpm.). REPLACE the exhaust manifold if unable to remove the casting flash/restriction. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test .

HF12 CHECK MANIFOLD VACUUM WITH MUFFLER/TAILPIPE ASSEMBLY DISCONNECTED FOR INDICATION OF A RESTRICTION

· Key off.

· Disconnect muffler/tailpipe assembly located after the catalytic converter.

· Repeat the vacuum measurement found in test step HF10 .

Did the vacuum needle QUICKLY rise above 54 kPa (16 inches-Hg) with the engine rpm at 2000?

Yes	No
There is a restriction in the muffler/tailpipe assembly. REPLACE the muffler/tailpipe assembly. REMOVE the vacuum gauge and tachometer. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test .	There is a restriction in the catalytic converter. REMOVE the vacuum gauge and tachometer. REPLACE the catalytic converter. INSPECT the muffler to be certain converter debris has not entered. RECONNECT muffler/tailpipe assembly. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test .

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