VCDS method of finding oxygen/lambda fault?

[Goran]

Ben, can the chip be re-coded to code out the post-cat lambdas?
I have had Wayne blocks on my car with 100cel cats for 2 years but have had some intermittent errors for the rear lambdas after the first year (but no CEL yet). I would like to just do away with those pesky rear lambdas.

I tried changing the engine code as per Tobes's instructions back on tyresmoke forums, but it wont take the code for Euro II. However it will take the code for a manual gear box for example, so perhaps the Euro II program isnt loaded on the ECU. Is there any other way to code out the rear lambdas without having to get a new chip?

Tobes' instructions:

"You need to select, Engine 01
then check the coding box,
This is the coding table

* ??xxx: Emissions
o 05 = Euro II/D3
o 06 = TLEV (USA)
o 07 = LEV (USA)
o 08 = GUS/China
o 10 = Euro III
o 11 = Euro IV/Japan
o 25 = South Africa
o 26 = Mexico/Taiwan
o 27 = Brasil
* xx?xx: Powertrain
o 5 = Front-Wheel-Drive
o 6 = All-Wheel-Drive without ASR/ESP (with CAN-Bus)
o 7 = All-Wheel-Drive with ASR/ESP (with CAN-Bus)
o 8 = All-Wheel-Drive with Post-Switch Stage (Low Range - A6 Allroad only)
* xxx?x: Transmission
o 1 = 6-Speed Manual Transmission
o 5 = 5-Speed Automatic Transmission (01V)
* xxxx?: Vehicle
o 2 = Audi A6
o 5 = Audi A6 Allroad

Write down the old code, The first 2 digits are whet you need, So if yours are 10 you need to change it to 05"

The above private message was as a result of this thread:
http://www.tyresmoke.net/forum/audi-...s-removed.html

Also, I was looking up lambdas on Elsawin, there is a bizzare statement on there that seems to indicate that rear lambdas take priority over front lambdas? I hope I havent affected fuelling by removing the rear lambdas out of the flow of the pipe. Seems a bit crazy to me I thought only front lambdas affected fuelling? (unless I mis-interpreted the upstream-downstream terminology)

Thanks