Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSBMW2006X5 (E53) V8-4.8L (N62)REPAIR AND DIAGNOSISA L L DIAGNOSTIC TROUBLE CODES ( DTC )TESTING AND INSPECTIONMANUFACTURER CODE CHARTSENGINE CONTROLS SYSTEM29F4
2006 BMW X5 (E53) V8-4.8L (N62)
29F4
2006 BMW X5 (E53) V8-4.8L (N62)SECTION 29F4
29F4 - P0420
Information saved in
DME
Fault code
29F4 - P0420
Fault text
Catalytic-converter conversion
Fault description
Catalyst System Efficiency Below Threshold (Bank 1)
Condition for fault identification
Test condition:
Oxygen storage capability
Catalytic converter temperature (model)
O2 sensor status
Fuel system
4g/sec. <= Exhaust-gas mass airflow <= 22g/sec.
Terminal condition: Terminal 15 on
Engine running
Voltage condition:
none
Condition for fault memory entry
40 sec./ continuous
Mean oxygen storage capability derived from three
measurements
Action in service
Conduct KAT system test
Replace catalytic converter as indicated
Fault effect and breakdown warning
Driver information
Warning light:
MIL on
Service instruction
none
Information saved in
DME
Fault code
29F4 - P0420
Fault text
Catalytic-converter conversion
Fault description
Catalyst System Efficiency Below Threshold (Bank 1)
Condition for fault identification
Test condition:
Oxygen storage capability
Catalytic converter temperature (model)
O2 sensor status
Fuel system
4g/sec. <= Exhaust-gas mass airflow <= 22g/sec.
Terminal condition: Terminal 15 on
Engine running
Voltage condition:
none
Condition for fault memory entry
40 sec./ continuous
Mean oxygen storage capability derived from three
measurements
Action in service
Conduct KAT system test
Replace catalytic converter as indicated
Fault effect and breakdown warning
Driver information
Warning light:
MIL on
Service instruction
none
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.