Smog Sensor not working LX 570 (1 Viewer)

[UCrazyKid]

Hey all, I did some searching and haven’t had much luck. The smog sensor that detects exhaust, etc and automatically changes the air to recirculate through the filter of the HVAC does’t seem to work anymore. I’ve tried. Adjusting the settings in the options menu, no difference. I have run Techstream scan and find no errors. I guessing that it is “workings but the sensor is blocked/dirty, etc or that whatever is used to “sense” volatile hydrocarbons has “worn out”. Anyone have experience with this? Can it be cleaned? Or just replaced? Thanks.

 

[TeCKis300]

That's a good question and I have no clue how that system works. Hopefully someone can chime in.

 

[TeCKis300]

Looks like there's an "Air Quality Sensor" or "Smog Sensor" located near the front grill. Not sure of its lifespan or if can be cleaned. About $120 for the factory part that's common to just about the whole Lexus lineup: 88898-50031.

 

[UCrazyKid]

Thanks @TeCKis300 ! I found the sensor, took it out and cleaned it. The unit comes apart to reveal a filter pad (dirty) and then a chamber with a sensor at the end of it. I cleaned the sensor with a few short blasts of MAF cleaner and then cleaned the filter with some compressed air. I put it all back together and reinstalled. We’ll see if that changes anything.
In the meantime I found my radiator is leaking where the top tank meets the aluminum, but NOT at my patch over the typical crack area from 4 years ago. I guess it is time at 130k miles. Also cleaned up some corrosion on the positive battery terminal. All and all some worthwhile maintenance work.

 

[hickuptruck]

As someone who's had many Lexuses and have thought it's broken even after cleaning it and also replacing it.

So in my LS430s,460 and LX470, I have that sensor behind my grill. I clean it every time I have access to it when I take the grill off. I open it up, take the pad out and clean it with dish soap. It's barely ever made any difference and 99% of the time it blows recirculate when I put it in auto setting (recirc/outside air auto button)

Then I found out that it will only switch to fresh air in the auto setting, when it's within 2 celcius (5 farenheit) of outside air temperature. Hence why it will blow recirc ac for 99% of the time in auto mode. That's why everyone thinks the sensor is broken but it's not. I've even tried it with a brand new oem one.