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Wideband sensors interchangeable?


Andrew

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Hey everyone.

Does anyone know if the Bosch LSU 4.9 sesnors are interchangeable between wideband controllers? AEM, Innovate, etc?

The sensor in my AEM has died. It looks like all of the 4.9s have the same connector and buying a part specifically for the AEM is basically twice the cost of the Bosch part but I'm suspicious they are identical.

AEM site talks about a resistor in the connector being calibrated to the sensor, but I'm guessing this is true if all 4.9 sensors, not specifically the AEM ones.

https://www.aemelectronics.com/products/sensors-connectors-accessories/wideband-sensors-bungs-accessories/wideband-o2-sensors/bosch-lsu-4-9-replacement-o2-sensor

 

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The sensor is the same however they all have variable resistance. If you were using a wideband controller that has open air calibration that is fine as it will learn the resistance during calibration. Afaik The aem is self calibrating which means if the resistance is different to what it expects it will read wrong. I assume they would be ensuring all the sensors are the same resistance by installing an offset resistor in the loom. Knowing that it means if you don't buy from them it may not read accurately. 

This is just my assumption though, it may not be accurate what I've said. 

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Thanks Roland. Yeah I think the offset resistor is in the loom, but the sensor loom because it is specific to the individual sensor.  What isn't clear is whether or not the wideband manufacturers have engineered in a difference, or are just implying that they have. 

While the AEM is self-calibrating it does also have a free air calibration feature , so I've got that option if I need it.

I might get in touch with Bosch and see what they say - I'll share the outcome if I get one!

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Hi again. In case it is useful for anyone else, I asked the question of Bosch, but the answer was pretty vague. I then asked AEM and was told:

Both the Bosch 17025 and AEM 30-2004replacement sensor part numbers have
been verified to work well with the X-Series wideband gauge.

 

So buying the general LSU 4.9 is fine, and I suspect this is true for Innovate, etc too. I also worked out what probably killed my sensor, so hopefully the next one will have a much longer life.

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13 hours ago, Skidpro said:

So, what killed your sensor ? It may help others to avoid the same mistake.

It was pretty silly. Basically spent a number of hours in January working on the car to service the ZF and fit an external transmission cooler and fan. Had accessories on to listen to music for parts of that time.

The relay for my wideband is triggered off accessories on, so would have been heating itself for all of time. Even short periods of this can kill the heater circuit on the sensor. 

Just forgot and didn't think to not do that or pull the fuse. I think I will find an ignition on source to trigger the relay instead.

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  • 2 weeks later...

OK so slight follow up here.  I plugged the new sensor in to test it resolved the issue before jacking up the car and removing the old one.  New sensor plugged in, still not heating.  Turns out one of the pins on the Deutsch connector I was using at the firewall was loose.

I soldered and heat shrunk everything and removed the connector and it is now fine.

So rather than saying the sensor was very sensitive to being left powered on with the car not running, I would now say it actually survived a decent amount of mistreatment exceptionally well!  And now I have a spare sensor for when it does eventually go bad :)

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