Audi Workshop Service and Repair Manuals > A3 Mk1 > Power unit | Simos injection and ignition system (4-cylinder) | Mixture preparation system, electronic inj.,Gas | Checking Lambda control | Check lambda probe heating Z29 for lambda probe downstream of catalytic converter

Test sequence

–	Unscrew protective cover -arrows- on vehicle floor.

–	Unplug 4-pin connector -1- (brown) for lambda probe downstream of catalytic converter -G130-.

–	Connect multimeter between contacts 1 and 2 to measure resistance.

t	Specification at room temperature 6.4 ... 47.5 Ω

If specification is not attained:

–	Replace lambda probe downstream of catalytic converter -G130.

If specification is attained:

–	Check the voltage supply to the Lambda probe heating.