With Manufacturer's Scan Tool

Oxygen Sensor Aging (Before Catalytic Converter) Testing

Special tools and equipment






- VAG 1788/10 Engine speed adjuster






- VAS 5051 and VAS 5051/1

Test requirement:
- Coolant temperature at least 80 degree C

Test sequence
- Connect the vehicle diagnostic, testing and information system VAS 5051, and select the vehicle system "01 - Engine electronics" from the menu. When doing this the engine should be idling. Connecting VAS 5051/VAG1551 Scan Tool






Display on VAS 5051:
- Select the diagnosis function "04 - Basic settings" from the menu -1-.






Display on VAS 5051:
1 - Enter display group
(figures up to 255)
- Using the keypad -2-, enter "034" to select Display group 034 and confirm entry with Q button.
- Set engine speed to 2000 RPM using VAG1788/10 RPM adjuster.






Display on VAS 5051:
- Check readout in display zone -4-.

NOTE: This process can take a few minutes.

Display Group 034:

Further notes
If the readout in display zone 3 or 4 does not match the specification:
- Take car for a test drive to free oxygen sensor of any deposits, then repeat the test.
If the readout in display zone 3 or 4 still does not match the specification even after the test drive:
- Replace the heated oxygen sensor (HO2S) -G39-.