02 sensor on 2009 yaris

[boujwali]

Hi, my yaris 2009 sedan is burning way too much gas...i have heard twice that its the o2 oxygen sensors. However the check engine light isn't on. 1. What type of sensors and how many does the yaris carry and where is it located...any one with pictures can assist

Thanks

[Bluevitz-rs]

The Yaris has a AFR (Air/Fuel Ratio) sensor. It is located in the header or close to it. It can be failing and still be within the computers acceptable parameters causing excessive fuel consumption. Mine went that way.

[boujwali]

oh ok thanks very much ill look for it again

[dogsridewith]

Any difference between an "Oxygen Sensor" and this "AFR sensor"? Does it output an analog voltage that can be read with a multimeter?
I ran a multimeter on my carbed 89 Tercel's O2 sensor (only one, in down pipe just below exhaust manifold) and it read so close to spec (.75 volt?) that I wasn't sure of the whole control circuit's function...was something driving that reading to .75 besides oxygen in the exhaust gas?

[Bluevitz-rs]

Any difference between an "Oxygen Sensor" and this "AFR sensor"? Does it output an analog voltage that can be read with a multimeter?
I ran a multimeter on my carbed 89 Tercel's O2 sensor (only one, in down pipe just below exhaust manifold) and it read so close to spec (.75 volt?) that I wasn't sure of the whole control circuit's function...was something driving that reading to .75 besides oxygen in the exhaust gas?

Yes an O2 sensor reads 0.0v - 1.0v.

0.0 is lean and 1.0 is rich. I'm not 100% on what afr that translates to but .5v should be an afr of 14.7. It's reading on a car that uses one will bounce up and down because the sensor has a slower response and the ecu with use an average reading to calculate the fuel delivery.

An AFR sensor reads from 5.0v - 0.0, and is opposite to an O2 sensor. It will read much more accurately and has a much wider range and is much faster.

The two sensors are NOT interchangeable.

[boujwali]

Not finding the o2 sensor on the yaris...my mechanic checked and found none

[07liftback]

Not finding the o2 sensor on the yaris...my mechanic checked and found none

I hope that was sarcasm... :bellyroll:

Anyways, I just changed mine which as Bluevitz-rs said, is located between the firewall and exhaust. You don't even need to get under the car, but it's hard to see from above. If you reach behind the engine on the driver side, you'll feel the sensor sticking out pointed towards the driver side (Make sure you do this when the car is cool!).

Spray some wd-40 or pb blaster on the sensor about an hour before you begin to make sure it comes easier. You could also use a breaker bar or a "cheater pipe" to gain better leverage.

The harness is right above it and it's wires are held in place with a metal clip where it easily slips out. You can just rent an oxygen sensor kit from Autozone and pop the oxygen sensor socket tool right over it and use a 3/8" ratchet to loosen it.

Oh and here's the sensor on Amazon, only $83 which is half of what the dealer is asking :biggrin:

Yaris Oxygen Sensor (http://amzn.to/2dunpYV)

[boujwali]

lol...wish it was sarcasm....lol thanks so much ill try locating it again!