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Toyota AF oxygen sensor ohms

  • babajis2010
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12 May 2019 22:42 - 13 May 2019 23:05 #29587 by babajis2010
Toyota AF oxygen sensor ohms was created by babajis2010
Hello experts in the house.
I would like to know how to specifically check the AF oxygen sensor ohms reading for my car. It thus appear Toyota has one part number for different ohms readings.
My car throws up P0420 and P0430 and I have done and change all parts and now I give up.
I finally stumbled on the repair manual that states 1.8 - 3.4ohms at 20degrees Celsius for my Toyota Avensis Verso 2002 ACM20L 1AZ-FE engine.
Car registration date: 21st August 2002
TecDoc ID 16026
Toyota dealership used my REG NO to order for brand new OEM AF sensors that both read 1.1ohms at 20degrees Celsius.
I am taking this case up with the dealership and I need you guys to point me in the right direction because the sensors don’t come cheap.

It’s such a bad and poor engineering by Toyota for having different ohms readings for one part number, why can’t they just change the part number if they are going to re-engineer the resistance.

I would really appreciate you guys help.
Last edit: 13 May 2019 23:05 by babajis2010.

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14 May 2019 13:19 #29644 by chief eaglebear
Replied by chief eaglebear on topic Toyota AF oxygen sensor ohms
hi sir still gotta do some studying on a/f ratio or wideband sensors I do know the voltage measurements are not the same as regular o2 sensors I don't think ohmage is the way to go to check proper operation since those are very sensitive circuits you need to do your checks under loaded conditions or when the circuit is powered up I do believe voltage measurments done at sensor are important but how those voltages are interpreted by computer is different in the sense that with these type sensors the computer is actually measuring current on that circuit one thing you might check is unklpug sensor and check for a bias voltage that will tell you wiring is good back to computer

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  • Dylan
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14 May 2019 13:39 #29645 by Dylan
Replied by Dylan on topic Toyota AF oxygen sensor ohms
You might wanna read this thread on A/F sensors written by Tyler.

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15 May 2019 08:32 #29660 by Tyler
Replied by Tyler on topic Toyota AF oxygen sensor ohms
It looks like you're measuring heater resistance, correct? If so, then I think I'd be OK with the readings you took. :) It's not exactly within range, sure, but I think it's close enough.

Is the car showing any heater circuit codes, or just the P0420/P0430? If no heater circuit codes, then I wouldn't dig further. In my experience, Toyota's heater circuit monitors are usually excellent at detecting any issues. Most of the ones I've seen are monitored for current in some way, and will flag codes for over and under a specific current range.

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