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Unread 8th January 2018, 10:59 PM
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Dulagarl Dulagarl is offline
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Default Oxygen sensor ultrasonic cleaning: it does work

I recently had an exhaust leak which gunked up my oxygen sensors. The right one in particular was very sluggish, alternating between maximum (0.89 v) and minimum (0 v) values and not much in between. This causes the sensors to compete against each other, resulting in surging at idle. (One sensor cause the engine to run lean and the other to run rich.)

I saw a vid on youtube which showed the use of an ultrasonic cleaner to clean oxygen sensors. I was sceptical, but thought that spending around $70 for an ultrasonic cleaner at Jaycar, before spending a stack on new sensors, was worth a try.

To my surprise it worked: very well.

Both sensors are now dithering in the mid range around 0.4 to 0.6 v most of the time. Engine is running smoother, economy is back where it should be, and there is no surging at idle. The sensors are basically doing exactly the same thing at the same time, although the right lags a little behind the left, and is probably on the way out. (that being said the sensors are not identical, and one is older than the other.)

It won't work on stuffed sensors, but dirty ones? it seems to.

It makes me think that a lot of sensors get replaced before they are actually stuffed.

For what its worth, I used de-mineralised water with a small amount of detergent for 90 secodns, then a fresh batch of de-mineralised water for a further 90 seconds, for each sensor. I let them dry thoroughly before re-installation.

here's the video that sent me in this direction.

FYI the vehicle is EZ30R Forester, ECU is vipec, and sensor performance (before and after) was monitored on the VIPEC software.
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Unread 9th January 2018, 03:10 AM
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Ratbag Ratbag is offline
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Very interesting info, Greg. Good to have this first hand experience.
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