Extenting wideband sensor life

[SimonSTI]

I'm about to wire a new AEM uego sensor and I've seen a lot of recommendation to delay it's start, especially when the engine is cold to avoid thermal shock on the sensor. Would be really easy to wire on a relay controlled by the ECU. Just checking if some have done it? What would be the logic, something like 20sec. delay if ECT under 50 degrees?

 

[Adamw]

Delaying power up may help.  What they are meant to have is low voltage to the heater during the condensation phase but you dont have any control over what the manufacturer decided in this case.  The suggested 20 seconds sounds ok.

[jigga009]

I have a logic set up for my per cylinder widebands. My G4+ controls a relay that powers the per cylinder wideband controller on 25 sec after the engine is running from cold (Engine Run Time > 25s), and turns it on immediately when the car is fired up AND coolant is up to temp (i.e. RPM>500, ECT>60 deg C). 

I also have a Link Lambda in my downpipe also has a 15s delay built in to it, but the ECU controls the staging of that directly so as not to get any error codes from the ECU regarding unexpected function of the wideband. The delay is whatever Link builds in to them from the factory. Not so concerned about this one coming on sooner since it is located behind the turbo.

I got the rough logic a little over a couple of years ago reading through some patent documents that were filed by GM or Suzuki (can't recall anymore) that explained how exactly they were controlling their oxygen sensors for max durability and efficiency on their passenger cars.

It's more complicated than above as Adam rightly suggested (I doubt he remembers, but Adam helped me with implementing what we could of what the OEMS are doing based on the illustrations from the patent docs I was able to dig up), as they are playing with voltage over time to effect how quickly the sensors heat up, but there were some elements of what they were doing that could be duplicated by the ECU, albeit in a less granular manner.

 

 

[koracing]

I would also make sure to use a RPM level so that your wideband doesn't just light up 20 seconds after key on if you were sitting there without the engine running. 

[SimonSTI]

Here is the logic I used, seem to work. 25s on cold start, 5s on hot restart.