|  |  | Results of the tests | 
| 0 | PRELIMINARY CHECKS | All OK | Problems met | Operation | 
|---|
| 1.6 16v 2.4 20v | Connect the tester (Examiner or Examiner Plus) and
transcribe the errors and environmental parametersCheck for the 'Mixture strength' error only | End of diagnosis | 'Upstream lambda probe' error
present | See
table    Z56 | 
| 'Upstream lambda probe' error present | Continue to Step  1 | 
| 'Upstream lambda probe' error present | Identify and eliminate the cause of the problem | 
| 1.2 16v 1.8 16v | Connect the tester (Examiner or Examiner Plus) and transcribe
the errors and environmental parametersCheck for the 'Mixture strength' error only | End of diagnosis | 'Upstream lambda probe' error present | See table    Z56 | 
| Only the 'Mixture strength', 'Misfire', 'Catalyzer' and/or 'Downstream Lambda
signal' errors are present | Continue to Step  2 | 
| Other errors present | Identify and eliminate the cause of the problem | 
| 1 | CHECKING SIGNAL PLAUSIBILITY | All OK | Problems met | Operation | 
|---|
| 1.6 16v | Check the plausibility of the MAP sensor signal. | Continue to Step 2 | The signal is not plausible | Replace the sensor  Op. 1056B44 | 
| 2.4 20v | Checking the plausibility of the flow meter signal. | Continue to Step 2 | The signal is not plausible | Replace the flowmeter  Op. 1056B12 | 
| 2 | ERROR DETAIL CHECK | All OK | Problems met | Operation | 
|---|
| 1.2 16v | Check the detail of the 'Mixture strength' error | End of diagnosis | The detail is 'Above the
upper limit' | See table    Z52 | 
| The detail is 'Above the upper limit' | See table    Z51 | 
| 1.6 16v | Check the detail of the 'Mixture strength' error | End of diagnosis | The detail is 'Rich system' | See table    Z51 | 
| The detail is 'Idle too rich' | See table    Z51 | 
| The detail is 'Lean system' | See table    Z52 | 
| The detail is 'Idle too lean' | See table    Z52 | 
| 1.8 16v | Check the detail of the 'Mixture strength' error | End of diagnosis | The detail is 'Above the upper limit' | See table    Z51 | 
| The detail is 'Below lower limit' | See table    Z52 | 
| 2.4 20v | Check the detail of the 'Mixture strength' error | End of diagnosis | The detail is 'Above the upper limit' | See table    Z52 | 
| The detail is 'Air leaks downstream of flow meter' | See table    Z52 | 
| The detail is 'Below lower limit' | See table    Z51 |