DIY : changing the Oxygen / O2 sensor on Yaris hatch MANY PICS

[07liftback]

Originally Posted by Cigar_Maverick

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On an unrelated note, when I took the console out, I saw these unused wires. This car does not have a lot of options, so I was just wondering what these would have been for. Power lock/windows?? see below:
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Looks like it's for the power locks. My Yaris came with power locks and the master switch is right next to the hand brake and shifter.

I just did my oxygen sensor and although it seemed impossible to reach from the top at first, it was MUCH easier getting at it from the front rather than crawling under the car. The only reason I got under the Yaris was to spray the PB blaster on it since I couldn't see what I was spraying when hovering above it.

Using a 3/8" drive ratchet and a oxygen sensor socket, I wasn't able to get leverage either above the car or below it so I had to attach a "cheater pipe" on the handle. It's basically a metal pipe from an old bedframe that I place over the ratchet and was able to get superb leverage without kicking or hammering the ratchet. I could probably use this cheater pipe without the PB blaster prep and still do okay.

Anywho, does anyone know if it's absolutely necessary to reset the ecu by unplugging the battery or will the car relearn the readings from the new oxygen sensor? I will continue without resetting the ECU to see when my MPG will finally improve.

[Cigar_Maverick]

Originally Posted by 07liftback

Anywho, does anyone know if it's absolutely necessary to reset the ecu by unplugging the battery or will the car relearn the readings from the new oxygen sensor? I will continue without resetting the ECU to see when my MPG will finally improve.

Honestly, I'm trying to remember if I unhooked the battery or, more likely, went to the local parts store and had them clear the errors. Almost certain I just had the codes cleared. No errors since.

[07liftback]

Originally Posted by Cigar_Maverick

Honestly, I'm trying to remember if I unhooked the battery or, more likely, went to the local parts store and had them clear the errors. Almost certain I just had the codes cleared. No errors since.

Did mpg improve right away?

[Cigar_Maverick]

Originally Posted by 07liftback

Did mpg improve right away?

Unfortunately, that is hard to say... The weekend I put the new one in, I also switched to Mobil 1 synthetic Advanced Fuel Economy, put a new air filter in and new plugs. I had just bought the car and didn't know the maintenance history. The total gained me 2.5 MPG. Going from 37.5 to 40. I am led to believe that, in my situation, the new sensor has minimal effect. That having been said, as they say, your results may vary. In hindsight I might have done a more controlled experiment, but I just hammered it all out at once. Maybe somebody else can chime in who has more experience with just installing the new sensor.