18 · Diagnostics

Z55 Catalyzer error

Make: Alfa Romeo
Model: 147 Factory Service Manual
Year: 2000–2002
Section: Examiner › Z55 Catalyzer error

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Fault diagnosisZ55 Catalyzer error

Z55 Catalyzer error

The instrument shows an error: catalytic converter

Step	Test procedure	Result	Action
0	PRELIMINARY CHECKS Connect the tester (Examiner or Examiner Plus) and transcribe the errors and environmental parameters Check the presence of 'Catalytic converter' error alone	OK	Incorrect selection of diagnostic procedure
		'Upstream lambda probe' error present	See table Z56 UPSTREAM LAMBDA SENSOR SIGNAL ERROR End of diagnosis
		'Mixture concentration' error present	See table Z50 MIXTURE STRENGTH ERROR End of diagnosis
		'Misfiring' error present	See table Z53 MISFIRE ERROR End of diagnosis
		'Downstream lambda probe' error present	See table Z58 DOWNSTREAM LAMBDA SENSOR SIGNAL ERROR End of diagnosis
		'Catalytic converter' error only present	Move onto step 1
		Other errors present	Identify and eliminate the cause of the anomaly. Move onto step 5
1	CHECKING FOR LEAKS FROM EXHAUST SYSTEM Look and listen to check the exhaust system from the cylinder head outlet to the downstream lambda probe. Check that there are no leaks	OK	Move onto step 2
1		Leaks are present	Restore the exhaust system seal and replace the affected parts if necessary Move onto step 5
2	ROAD TEST TO CHECK CONCENTRATION Road test the vehicle and use a tester to check concentration status in 1st and 2nd ring while operating in closed loop Check that activation takes place properly	OK	Move onto step 3
		Activation does not occur properly in first ring	See table Z56 UPSTREAM LAMBDA SENSOR SIGNAL ERROR End of diagnosis
		Activation does not occur properly in second ring	See table Z58 DOWNSTREAM LAMBDA SENSOR SIGNAL ERROR End of diagnosis
3	CHECKING INLET AND EXHAUST SYSTEM SEAL Check the exhaust system and ensure there are no leaks from the cylinder head outlet to the upstream lambda probe See Test 1072A Intake and exhaust system leakage check to check seal of the inlet and exhaust system	OK	Move onto step 4
3		Seal incorrect	Restore system seal and replace the affected parts if necessary Move onto step 5
4	REPLACING CATALYTIC CONVERTER Replace the catalytic converter Op. 1080B62	OK	Move onto step 5
4		Not OK	End of diagnosis
5	DELETING AND CHECKING ERROR Use a tester to cancel the errors in the control unit Carry out a road test and ensure the error does not recur	OK	Move onto step 6
		Anomaly persists, this step has been reached for the first time and the catalytic converter has not yet been replaced	Move onto step 0
		The anomaly persists, but this step has been reached for the second time or the catalytic converter has already been replaced	Contact Technical Service for further information on the problem End of diagnosis
6	CHECKING CORRECT OPERATION Check that the fault is no longer present	OK	Incorrect selection of diagnostic procedure
6		Fault persists	Incorrect selection of diagnostic procedure

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Parts & tools for this job For 2000 Alfa Romeo 147

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