Air Fuel Ratio Sensor

[bbell]

I have a 2000 RX300. The check engine light came on and the reading was a faulty air fuel ratio sensor. I had heard there were two sensors? If so, how do I find out which needs replacing? Can I go with the sensor I can purchase at AutoZone or should I buy it through the dealer?

My husband is going to replace it but because I'm home during the day I am the one doing the due diligence; and I don't know much about cars and car parts. Thanks ahead of time!!

[djspawn00]

I reccomend you stick with Denso brand A/F sensors. To find out which sensor you need to change you need to find out what codes where pulled. You can get the codes read at autozone and post them up here. The codes specify the location. Goodluck.

I got my sensors for my 00 Solara (SAME ENGINE AS RX300) at rockauto.com, its a lil cheaper there and these sensors do cost an arm and a leg no matter where you get them from but rockauto had much better pricing than autozone.

[code58]

I have a 2000 RX300. The check engine light came on and the reading was a faulty air fuel ratio sensor. I had heard there were two sensors? If so, how do I find out which needs replacing? Can I go with the sensor I can purchase at AutoZone or should I buy it through the dealer?

My husband is going to replace it but because I'm home during the day I am the one doing the due diligence; and I don't know much about cars and car parts. Thanks ahead of time!!

www.factorylexusparts.com $150.

[code58]

I have a 2000 RX300. The check engine light came on and the reading was a faulty air fuel ratio sensor. I had heard there were two sensors? If so, how do I find out which needs replacing? Can I go with the sensor I can purchase at AutoZone or should I buy it through the dealer?

My husband is going to replace it but because I'm home during the day I am the one doing the due diligence; and I don't know much about cars and car parts. Thanks ahead of time!!

bbell- If you go with Rockauto, the # you SHOULD need is Denso 2349009- same as original Toyota/Lexus 89467-41011. If you take a mirror (if your lucky, the # is facing up, if not, you'll need a mirror), the # is laser etched on the barrel of the sensor and isn't real easy to read but with a flashlight and good eyes you CAN see it. The front and rear sensors are the same so you can double check the # on the front sensor but the sensor you probably need is the rear. They are mounted in the exhaust mainifolds, front and rear. The one in the cat. conv. outlet is different. The code that you read with the obdII scanner will tell you whether it is front or rear. I believe you are much better off using original eq. Denso sensors- from whatever source you choose to get them. B2S1 will be front (easy one) and B1S1 will be the rear exhaust manifold. Good Luck!

[lahermano]

So did u guys replaced yourselves ?

how difficult was it ?

I am in the same boat need to replace the 2 Air fuel ratio sensors. please suggest ....

thx

I have a 2000 RX300. The check engine light came on and the reading was a faulty air fuel ratio sensor. I had heard there were two sensors? If so, how do I find out which needs replacing? Can I go with the sensor I can purchase at AutoZone or should I buy it through the dealer?

My husband is going to replace it but because I'm home during the day I am the one doing the due diligence; and I don't know much about cars and car parts. Thanks ahead of time!!

bbell- If you go with Rockauto, the # you SHOULD need is Denso 2349009- same as original Toyota/Lexus 89467-41011. If you take a mirror (if your lucky, the # is facing up, if not, you'll need a mirror), the # is laser etched on the barrel of the sensor and isn't real easy to read but with a flashlight and good eyes you CAN see it. The front and rear sensors are the same so you can double check the # on the front sensor but the sensor you probably need is the rear. They are mounted in the exhaust mainifolds, front and rear. The one in the cat. conv. outlet is different. The code that you read with the obdII scanner will tell you whether it is front or rear. I believe you are much better off using original eq. Denso sensors- from whatever source you choose to get them. B2S1 will be front (easy one) and B1S1 will be the rear exhaust manifold. Good Luck!

[SouthamptonLexus]

I have a 2000 RX300. The check engine light came on and the reading was a faulty air fuel ratio sensor. I had heard there were two sensors? If so, how do I find out which needs replacing? Can I go with the sensor I can purchase at AutoZone or should I buy it through the dealer?

My husband is going to replace it but because I'm home during the day I am the one doing the due diligence; and I don't know much about cars and car parts. Thanks ahead of time!!

bbell- If you go with Rockauto, the # you SHOULD need is Denso 2349009- same as original Toyota/Lexus 89467-41011. If you take a mirror (if your lucky, the # is facing up, if not, you'll need a mirror), the # is laser etched on the barrel of the sensor and isn't real easy to read but with a flashlight and good eyes you CAN see it. The front and rear sensors are the same so you can double check the # on the front sensor but the sensor you probably need is the rear. They are mounted in the exhaust mainifolds, front and rear. The one in the cat. conv. outlet is different. The code that you read with the obdII scanner will tell you whether it is front or rear. I believe you are much better off using original eq. Denso sensors- from whatever source you choose to get them. B2S1 will be front (easy one) and B1S1 will be the rear exhaust manifold. Good Luck!

before you start make sure you spray some PB or WD40 on them to help break up the rust and if you can find the o2 sensor tool that looks like the close end of wrench use that instead of the socket one with the slit down the side.

[Gitano]

I understand to remove the oxygent sensor you move the driver seat forward and tilt it up there betwen the vent outlet and the  left side of the seat there is a cut in shape of a + you have to cut headed to the front of the seat about six inches making sure to just cut the carpet and not the wires that come out from the floor runing to the left were they connect.  Then you make the other cut going towards the left side about six inches this will alow you the access to the connection. Then pull it out from under the floor. The rest is under the vehicle taking the sensor off and replacing it. On  the drivers side there is yet another panel which is for replacing the fuel pump,  which is inside the tank.

Edited November 23, 2016 by Gitano
Correction

[Drew707]

 

I understand to remove the oxygent sensor you move the driver seat forward and tilt it up there betwen the vent outlet and the  left side of the seat there is a cut in shape of a + you have to cut headed to the front of the seat about six inches making sure to just cut the carpet and not the wires that come out from the floor runing to the left were they connect.  Then you make the other cut going towards the left side about six inches this will alow you the access to the connection. Then pull it out from under the floor. The rest is under the vehicle taking the sensor off and replacing it. On  the drivers side there is yet another panel which is for replacing the fuel pump,  which is inside the tank.

Just saw this and would like to say...

The downstream O2 sensor is easily accessible from under the car.  It sits on the driver's side of the exhaust pipe between the cat (fore) and resonator (aft).  You should not need to cut anything within the cabin to reach it.  You should be able to do it without ramps or a jack.