Why do I keep burning up WBO2 sensors?
 

I have an LC2, was fine NA for 3 months, installed turbo, 3 months later got an error 8. Called Innovate and they said replace the sensor, which I did. 2 months or so go by, fails again. Was at the drag strip and it failed after a 2 step launch, maybe thats what killed it. So I replced it again. Now this is about 1 month or so later and I'm getting another error 8. No 2 step or anything, just normal (spirited) driving. I'll be cruising along and the AFR will show normal, sometimes stick high or low, then start flashing 7.4. I called Begi and Stephanie said the position of the bung is ok, but I think it is too low... the alternative would be one of the bungs further up the DP, but then the sensor would only be a foot of so away from the turbo. Would I be better off putting the sensor up there?

Attachment 233244

Attachment 233245

Thanks,

Andy

Where is the O2 sensor currently located (distance from turbo and clock position)? You never mentioned that.

EDIT: Never mind. I see the pictures now.

To quote the LC-2 manual: "Using a clock as reference, mount the bung between the 9:00 o’clock and 3:00 o’clock position. Welding the bung in the lower section of the exhaust pipe can result in sensor damage caused by condensation making contact with the sensor’s internal heating element."

It looks like your sensor is lower than 3:00 o'clock.

Yeah I agree that it's too low. I think I'm gonna use the second bung up by the turbo for now, then next time I have the DP out I'll weld a bung in a better spot.

Heat sink it. Copper pipe smashed and drilled works great.

Mount it between 9 and 3 O' Clock and put a heat sink on it. Done.

Quoting the LC-2 manual again: "Weld the bung at least 24 inches downstream of the exhaust port outlet (after the collector), or 24 inches after the turbocharger if so equipped. The bung should be welded before the X or H pipe if so equipped."

I've never messed with heat sinks, but Innovate spells it out pretty simply. Closer than 24 inches to the turbo could damage the sensor.

I will weld a new bung on next time I take the DP out in a good spot according to their instructions. But for now I'm gonna try and get Autozone to warranty this sensor like the did last time and try it out in the other bung. I tacked the 2 piece slip joint together so it's a biotch to get the DP out or else I would do it the right way this week.

Probably either the low in the pipe condensation problem or a bad ground. I had a car that had the sensor last for nearly a year and then something happened and I couldnt get sensors to last for more than 2 months. That LC1 is in the WRX now and its been in for like 2.5 years, and that LC1 spent a trip on the highway sitting on the downpipe so its nice and melted. So it has to be something like a bad ground that was making the sensors show bad on the previous car.

Innovate allows closer mounting with heat sink. They have instructions as to preferred shape.

Your wideband sensors angle is in the total opposite position it should be, condensation needs to be able to run off it not in to the sensor itself, correct distance from the turbo also.

Amazingly, autozone warrantied the sensor for the 2nd time, so I relocated it and fabbed up a crude heat shield out of a piece of an old street sign. Hopefully this takes care of the E8 for now, as this location is a pain to get the sensor in/out...

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If it dies again, I'm going to ditch the LC2 for something better...

It's unreasonable to blame the LC-2 for your problems. You've installed your sensor against the manufacturer's recommendations causing it to be damaged. Additionally, if you had any other wideband controller, the sensor would be damaged in the exact same way. Changing your controller doesn't mean your sensor is suddenly more resistant to your ignorance.

You're right. I guess the final effort will be welding in a new bung as far down the pipe as possible, and on the upper half of the pipe. But that ain't happening for a little while, probably not until I pull everything out to swap in my project built motor in a few months.

It will absolutely be fine where it is with its heatsink.

Also the sensor isnt an innovate sensor, it is a Bosch LSU4.2, which is what basically every single oem on the plant has used for 10 years on every model.

Its your fault not its fault.

Dann

Innovate's heater control is garbage. I've run actual Bosch wideband systems (ETAS brand) and they don't overheat like that with the 4.2 or 4.9 .

How is innovate's heater control garbage? It says here on Innovate's website that the LC-2 uses "Bosch™ Heater Control". I would assume Bosch's own brand uses the same "Bosch™ Heater Control".

Also, I don't think heater control is the issue here. If you install a sensor too low in the pipe, it can be damaged by condensation contacting the heating element. I'm not positive, but I doubt better heater control can help this. And I can only imagine that the Innovate unit with "Bosch™ Heater Control" is designed to take into consideration things like condensation in the exhaust.

Finally, if you install a sensor too close to the exhaust source, it can be damaged by overheating. I'm not sure a controller can help this issue because the heating element is only used to preheat the sensor. The heating element and controlling circuit (such as the "Bosch™ Heater Control" in the Innovate brand unit) can't do much to cool the sensor off if the exhaust gasses are overheating it.

I have done what the OP did, and it burns up the sensor from overheating it. I kept it in the same spot, put a copper heatsink on it and it never failed again.

Just saw this on a 2011 lexus is250 at work:

https://www.miataturbo.net/attachmen...ine=1434141787

Tried looking up a part# for the cover only, but it looks like it comes as part of the sensor. Looks like it'd work great tho!

https://www.miataturbo.net/attachmen...ine=1438893151


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