Engine Controls - DTC's P0421/P0431 Set

Service

2

28/09 ENU 2613

Nov 3, 2009

The present document was valid at the time of print. A later version may be available online

Fault code P0421/P0431: Warm Up Catalyst Efficiency Below Threshold (28109)

Model year:

as of 2009

Vehicle Type:

911 Carrera/911 Carrera S

Concerns:

Oxygen sensor upstream of catalytic converter

Information:

Replacement of catalytic converters that are not defective.

Catalytic converters were replaced because of the fault codes P0421/P0431 Warm Up Catalyst Efficiency Below Threshold" stored in the DFI control unit.

Analysis performed on the removed catalytic converters have shown that there were often no malfunctions in the catalytic converters - the fault was caused instead by damaged oxygen sensors.

Action Required:

Carry out the following measures for the fault codes mentioned above.

1 If the catalytic converter shows no signs of mechanical damage on the carrier

(detachment/fusion/breaks and so on), replace the pre-catalytic converter oxygen sensor on the affected cylinder bank.

2 After replacing the oxygen sensors, run the short test in accordance with the Guided Fault Finding (GFF)" instructions using the PIWIS Tester.

3 On vehicles whose engine was manufactured before the date of introduction specified below, also fit a heat shield close to each of the primary catalytic converters on the engine.

Date of Introduction:

June 5, 2009, as of the following engine numbers:

MA101A00786 - 911 Carrera
MA102A01139 - 911 Carrera S

Parts Info:

997.113.209.30 --> Heat shield, left
997.113.208.30 --> Heat shield, right
900.385.009.01 --> Torx screw, M6 x 16 (8 ea. required)

Work Procedure:

1 Replace the pre-catalytic converter oxygen sensor for the affected cylinder bank (depending on the fault code), see section on 246919 Removing and installing oxygen sensors upstream of catalytic converter

2 To check the primary catalytic converters, run the short test in accordance with the Guided Fault Finding (GFF)" instructions using the PIWIS Tester.

3 Fit heat shields, if they are not already installed. See section --> 261319 Removing and installing cover plate for exhaust manifold

Working Time:

26132400: Installing two cover plates for exhaust manifolds Labor time 200 ZE

Includes Removing and installing oxygen sensors

997110, 997111, 997120, 997121, 997140, 997141, 997310, 997311, 997320, 997321, 997410, 997411, 997430, 997431, 997510, 997511, 997520, 997521, 997610, 997611, 997620, 997621

Model year as of 2009
C02, C36