I was reading: https://www.audiforums.com/m_335069/tm.htm which i made as a sticky because is seems very informative and usefull.

Anyway... I have been detonating lately under load, so I was researching on fuel trim etc. It says in that link to check block 32 with vag and that the values for the first 2 fields should be no more than +/- 10%. It says that a value of 0% means that something is wrong, or codes have just been cleared-(which is not the case for me).. My first field reads a steady 1.1% (as if there is no adjustments being made to the A/F mixture at idle. And the 2nd field which represents adjustments under engine load is stuck at 0% while driving. Could this mean that my 02 sensor is shot? I did have a lamda fault code last week that said the signal was too high (forgot fault code # but in bently it mainly pointed to the heated oxygen sensor). And i have had a lean code before which pointed to the MAF, and it was replaced along with the ects. Any ideas??? Still happening.
Yes I use premium and correct spark plugs gapped correctly. I also have run injector cleaner though it.

 

have you checked all the hoses/vacuum pipes for leaks?? have you cleaned the throttle body out?? VAG can throw you off the fault you need to check the basics

 

Yes I checked 2 weeks ago when it first started happening for leaks etc. No I have not cleaned out the Tbody.. But if it were a gunked up Tbody id be sputtering/hesitating more like running rich. My question is for people who are familiar with vag and reading fuel trim values with it. It seems that there are no adjustments being made to the AF mixture during idle and also under load. What makes me wonder the most is the 0% value in the second field for what adjustments are being made under load.

 

when the butterfly valve in the throttle body sticks due to carbon build up more so on the turbo this is where you start

 

in the old days I used the throttle flap/butterfly valve to keep the revs up by turning the throttle stop screw which was required to keep the off roader running before the race

 

If the throtle plate/butterly valve was sticking i would be restricted of air in the combustion process and would therefore run rich, not lean. When you run lean, that means too much air, or that fuel is getting burned too soon which causes detonation.

 

possible but the throttle flap not closing fully could cause the same problem as the ECU sets to 0% when the peddle is off, its all down to electronics and values this is where the system fails

 

Thanks for your help.. Any experienced vag users got any help for me????
Are there any experienced vag users?

 

Ive been in the process of checking these diagnostic systems out and im sure you know the recent results ( they only point to a possible area ) without the consideration of how the engine and electrics work and why problems occurs so I vote these new diagnostic tools as very basic

 

Yes for fault codes you are right. But with measuring blocks in vag com you can look very in depth into electronics. This is what my question is all about.