HELP!!! Vigas lambda 40

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Stonefire

Member
Oct 23, 2014
9
massachusetts
fighting a lamda problem on my vigas 40 lamda reading is always 1.99 no matter what time I check it, which I think is what is causing my servo to stay at 45% which only lets primary air at the burn, the servo motor moves freely and is adjusted correctly it does cycle correctly from 0% to 100% upon start up but always runs back down to 45% with 1 min of start up! Anyone have any suggestions?
 
Not an owner, but....
Do you have to go to a special maintenance screen to see error codes?
I just did a search on 'diagnose o2 sensor' and there's plenty of videos for cars involving multimeters, propane torch, etc-you could eliminate the sensor.
 
I know what the boiler is, what make and model is the sensor? What color was the tip before you cleaned it, is it the original sensor?
I looked all over for a serial # or brand on the o2 sensor didnt find anything, it is a four wire sensor two whites which is a heating element and a black and a gray which is the sensor circuit i was just going to replace it but not sure if i can get a automotive part that matches it without a part number on it. the tip was brownish black when i cleaned it
 
dealer told me to clean it and check connections and to go on youtube to see how you test a sensor is good or bad
And the sensor tested bad?

How much does your dealer want for a replacement. A Bosch four wire wide band sensor is going to run 150ish at Napa.
 
Can you post a pic of the sensor, more than likely it's a Bosch lsm11, a industrial sensor not available at auto parts stores. I assume you cleaned with compressed air? To check the sensors responsiveness and burn any crud out of it, try a propane torch on the tip of the sensor. Don't be afraid to turn it cherry red for a few seconds, watch the o2 display, under propane it should read 0pct o2, as it cools it should methodically escalate to its high calibrated scale of 20.9. Let me know what the response is. I assume this problem happened from one burn to the next and not over a period of time.
 
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