S2 with AAN ignition mixture rich, cannot find possible cause

[qba]

I'm beginning to think that there might be something wrong with the ECU from the inside. Some sort of short connection or smth. Tomorrow is a day also so I will go on...

[prj]

so did "qba" have 0.6 or 0.4 ... ? what dash said ? and if he have 3b engine it must be 0.3... MUST..

No. Stop being obsessed with it.
If I program my idle lower the vacuum will increase. If I program it higher, it will decrease.

[qba]

Try getting into o sensor wire near the ecu and measure voltage again.You said 0.3ohm..
I'll measure mine tomorow.
If the probe disconected shows aprox stoich and when conected ecu sees lean it means stoich measured under the hood is not the same as voltage readed by ecu in the car.
Get a separate wire for probe signal to ecu.

we measured it from the both sides. From the ECU pin the voltage was the same as from under the hood. ECU doesn't see lean. It shows normal. It "Acts" as there were no lambda present. I mean lambda doesn't make any difference in ECU at all.

[newsh]

If the ecu has had sockets fitted, maybe a bad connection

[qba]

This ECU indeed has had sockets fitted. Might be worth to look into it

EDIT: BUT I forgot allready that I tried two ECU-s and had the same result. One of them didn't have sockets the other one did.

[newsh]

Its worth a look, and make sure the chips are well seated.

[UrS4boy]

Did I miss it because I don't see that the G62 ECU coolant temp sender screwed into the back of the head was tested and found to be fine (or not)?

[qba]

Yeah, you missed it. Post 8. I changed the sender few days ago just in case. Both work fine.

[prj]

If the ecu has had sockets fitted, maybe a bad connection

No, this is not possible. It can not affect lambda.
The chips are just memory, if anything was wrong with them, the car would not start at all.

[qba]

Well, then I don't have anything to hang on to anymore?

[prj]

Try what pasbogdan said - get a separate wire from the lambda probe to PIN 28 on ECU.

[qba]

Will do that.

[prj]

And lend a wideband

[qba]

Finding a wideband on an island turned out to be quite complicated, lots of guys have sensors but no controllers.

[prj]

All you need is ~130 EUR and some soldering skills

http://14point7.com/SLC-DIY.php