Reefo11

Hello,

I have read the threads but could not find anything on what I need to ask. I hope you Lexus/Denso experts out there can help me out on this...

A bit of background: I own a 2nd Gen Lexus '2005 RX300 (1MZFE) imported from the Singapore market. I do not believe similar model of the RX300 was ever released to the US market - you guys went straight from the old 1st Gen RX300 to 2nd Gen RX330 (3MZFE). Obviously the difference was mainly the engine cc as the name suggests.

Anyway, I have a check engine and VSC lights on. I ran the diagnostics on my RX300 and found that I need to replace the "O2 sensor Bank 2 Sensor 1". Found the location of the sensor. So far, all is clear.

Went online and found several Denso O2 sensors (mainly for the RX330 and RX350). Before I purchase anything.. I have some questions:

1) Would I be able to use the O2 sensor for the RX330/RX350 if it is physically an exact fit to my RX300 (I believe it is)?

2) Would the difference in engine cc (3.3L V6/3.5L V6 vs 3L V6) affect the O2 sensor inputs to the car's computer?

3) Has anyone got a list of part numbers for the O2 sensors found on the RX300?

I hope I was able to describe the issues and questions clearly to you guys. English is not my 1st language. Please do tell me if you need more information.

Thank you and I hope to hear your responses soon.

Reefo





RX300

5W40

I would follow the engine model not the year model

North Amercian Model:

2003 RX300 1MZFE

Part Number: 8946748011 Front
Part Number: 8946549075 Rear

But I will use Denso 234-9009 Oxygen Sensor/ Air- Fuel Ratio Sensor for Ft. instead.

2004 RX330 3MZFE

Part Number: 8946548170 Front
Part Number: 894650E010 Rear

Denso 234-9042 Oxygen Sensor/ Air- Fuel Ratio Sensor for Upstream L/R instead

Reefo11

Hey thanks for your reply. Apologies for the delay in replying, it's the holidays over here. I appreciate the part numbers you gave me and the Denso 234-9009 was actually the one I was looking at online for my car. I understand the AF sensor and the O2 sensor has similar functions - with the AF sensor being more sensitive. Quick questions though:

1) Would it be okay to install the AF sensor in place of the O2 sensor?

2) Would the diagnostics still pick it up as "Check Engine" as it is not the part that was meant to be put there?

I appreciate anyone's inputs in the matter. Thank you.

5W40

It really depends your error code scanned

If I were you, I may first clean the MAF, clean or replace air filter ,check the hoses attached at the back of air filter box and disconnect battery for 30 min. and then drive it and see!

AFIK:

1) yes
2) if the sensor is culprit then you should be fine.

JoeInHNL

The AF sensor (also known as a wideband O2 sensor) and the O2 sensor (narrowband sensor) output signals are very different. They are not interchangeable.

Decent explanation here

http://www.enginebasics.com/EFI%20Tu...%20Basics.html

That said 234-9009 is an air-fuel sensor and should be the correct one for your issue. Sensor 1 is the upstream sensor and is an air-fuel sensor.