I just got my vag-com in the mail today and ran the trial version of ross-tech software 409.1 on my 2000 audi a4 1.8t quatro.
I don't have a CEL on but I did get this fault. only had the car a few weeks and trying to get up to speed on it. any info about this fault would be great to know.

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Address 01: Engine
Controller: 4B0 906 018 Q
Component: 1.8L R4/5VT G 0006
Coding: 07251
Shop #: WSC 06335
1 Fault Found:
17521 - Oxygen (Lambda) Sensor: B1 S1: Internal Resistance too High
P1113 - 35-10 - - - Intermittent
Readiness: 0000 0000

 

Clear the code and see if it comes back. If it does, then your primary 02 sensor is probably shot. If the CEL is off then its probably old news/issue. Normally 02 sensor codes trigger the CEL. So it might just be stored from a long time ago- maybe when it was replaced, and no one ever cleared the code....

 

totally agree with^^^ old stored code because it is intermittent

 

thanks guys I'll clear that when I get home and take it for a spin. is it something that will trip the code quickly.. do I need freeway driving?

 

its a common code when you hit ice cold water on the road ( it shocks the O2 sensor ) and the codes is stored in soft mode so doesn't put the CEL on because its not a problem but if it comes back 3 times after clearing it then its a problem