Setting up 4.9 LSU on 3.6 board

[Machismo]

It might not be the sensor, because today I connected another, brand new 4.9 and tried to calibrate it. It kept saying 'increase calibration value' even though I maxxed it at 255 already. The config values have not changed, so I guess it's something electrical at the board..
I know it's not the heater since the sensor heated up normally.

[VEMS]

Hello Machismo,

In cases like this, start at the beginning:

* check connector crimps on both sides
* wiring, shorts, perhaps some wiring melted from running close to exhaust ?
* perhaps one (or more) of the contacts were not inserted all the way and make bad connection ?

All of the above is much more likely than any controller problem.

Best regards, Dave

[Machismo]

I examined the board closely and found one problem, the nernst voltage 27k resistor wire had worked itself off at the pin 13. It probably happened when I had a passenger couple of days ago and he streched his legs at the wiring. I still have a temporary wiring because of the constant changes and because of the stock ecm backup possibility at this point.

However I connected it back but the problem continues even though nernst voltage is now back to normal. I wonder if the loose wire had the chance to create some kind of shortcut. The wire was pretty stiff, but it might have hit EC18 pin 7 (WB02 pump - ).

[Machismo]

I didn't find any other faults, so I restested with the new sensor. It was then I noticed that I had made a mistake the first time, the sensor had heated, but only engine running and not when I tried to calibrate it. Im my case the sensor heating is connected to fuel pump relay so it was too easy to make a mistake there...

Anyways, now that I connected the new sensor and the nernst voltage is ok, the wideband is working perfectly again!

Only thing that troubles me is that why the sensor went kaputt... Does too low nernst break it or was it the exhaust backfires/popping that my car has? On the other hand, much older 4.2 sensor on the other pipe is still working normally, so exhaust conditions are not impossible. This is a natural aspirated engine.

The 4.9 sensor that broke was specific to some car, I don't know which. It was quite large opening Bosch LSU4.9 lambda 0 258 017 115 with a short connection wire.

The one I replaced it is Bosch LSU4.9 Universal lambda 0 281 004 148 with much smaller holes and a longer wire. I hope the more protective cover will shield it from backfire?