The diagnostic socket is located in the central console next to the ashtray.
expand_moreIdling speed with automatic gearbox
expand_moreAll other modifications
ACK engine
640–760 rpm640–760 rpm640–760 rpm
ALG engine
740–860 rpm740–860 rpm740–860 rpm
AMX engine
720–820 rpm720–820 rpm720–820 rpm
APR engine
650–750 rpm650–750 rpm650–750 rpm
AQD engine
720–820 rpm720–820 rpm720–820 rpm
expand_moreIdling speed with manual gearbox
expand_moreAll other modifications
ACK engine
640–760 rpm640–760 rpm640–760 rpm
ALG engine
740–860 rpm740–860 rpm740–860 rpm
AMX engine
720–820 rpm720–820 rpm720–820 rpm
APR engine
650–750 rpm650–750 rpm650–750 rpm
AQD engine
720–820 rpm720–820 rpm720–820 rpm
Minimum engine oil temperature at VET
176°F176°F80°C
expand_morePetrol exhaust gas values
expand_moreCO content at idling speed
All other modifications
0–0.5 %0–0.5 %0–0.5 %
expand_moreCO content at increased idling speed
All other modifications
0–0.3 %0–0.3 %0–0.3 %
Delta lambda
0.03 λ0.03 λ0.03 λ
expand_moreIgnition time
expand_moreADP engine
Setting
°00'±3°00' - before TDC + after TDC
Test value
°00'±12°00' - before TDC + after TDC
Carry out basic adjustments using suitable diagnostic unit.
expand_moreIncreased idling speed
All other modifications
2500–2800 rpm2500–2800 rpm2500–2800 rpm
expand_moreLambda sensor design
All other modifications
Jump type lambda sensor
Lambda value
0.97–1.03 λ0.97–1.03 λ0.97–1.03 λ
Maximum HC content at idling
100 ppm100 ppm100 ppm
expand_morePetrol conditioning speed
All other modifications
2500–2800 rpm2500–2800 rpm2500–2800 rpm
expand_morePetrol conditioning time
All other modifications
120 s120 s120 s
expand_moreSpeed for disturbance variable
expand_moreAll other modifications
ACK engine
540–860 rpm540–860 rpm540–860 rpm
ALG engine
640–960 rpm640–960 rpm640–960 rpm
APR engine
550–850 rpm550–850 rpm550–850 rpm
AQD engine
620–920 rpm620–920 rpm620–920 rpm
expand_moreTest speed for lambda sensor signal
All other modifications
720–820 rpm720–820 rpm720–820 rpm
Voltage swing at test speed
0.3 V0.3 V0.3 V
More than
To reduce environment impact and pass government inspections keep emission parameters at the level prescribed by Audi.
Please be noted that all capacities listed here are approximate. Check fluid levels when adding or refilling as recommended in your 2001 Audi A4 user's manual. Keep in mind that all information here is provided “as is” without any warranty of any kind.
Before doing any DIY service please check your insurance policy and Audi warranty policy for your region. In some regions DIY service may invalidate your warranty.
DIY car service is not as difficult as it looks like and it might save you thousands of dollars per year. It might be even fun and a good thing to do with your kids on a weekend to teach them how basic machinery works. It's really hard to screw something up and damage your car permanently if you use right tools, follow Audi A4 service manual and use right parts and fluids in prescribed amounts. Even modern cars stuffed with electronics can be serviced in your garage or even in your driveway. Changing engine oil, brake fluid, ATF, replacing brake pads, and etc. It's all may be done by yourself in a mater of a couple of hours.
Doing basic service for your 2001 Audi A4 you're not only saving money, but also also improving your technical skills and learning something new.
2001 Audi A4 generations
In 2001 Audi offered 2 generations of the A4. Emission may vary in different generations. Be sure that you are looking at the rigt modification.