IS300 O2 sensors

[DF-300 Sport]

.....has anyone had 'O2' sensor replacement issues?... my '05' IS300 sportcross is showing O2 sensor fault codes and i am trying to source the correct ones by my  mechanic....Lexus main dealer have been called but they don't have that in-depth knowledge (or are deliberately being unhelpful)? Lexus parts are x3 more expensive! Changed 2 (pre and post cat) on the 1st bank and same fault is still showing....

Car is still driving like a dream (with the engine warning light illuminated) and only 92k miles, with 2 x cam belt changes and fairly recent spark plug changes (2020), love this car!

[ColinBarber]

14 hours ago, DF-300 Sport said:

same fault is still showing....

Do you know the fault code(s)? Depending on code it may not be the sensor at fault.

Nothing really special about the O2 sensors on the IS300, unlike some Lexus vehicles that use the more expensive Air/Fuel ratio sensors.

I always recommend Denso sensors, either the ones you get from Lexus directly, OEM ones or their aftermarket replacements - they are all the same quality. Other makes in theory should be fine but they sometimes have different resistance on the heater circuits which cause errors.

 

At the bottom are the Denso parts you need for the IS. The only difference in bank 1 and bank 2 is the lead length. I've purchased from sparkplugs.co.uk before, and autodoc probably stock them as well. 

[DF-300 Sport]

Thanks for this info Colin, really appreciate the reply!.... Not sure what the actual code letters/ numbers were (it was a "snap-on" diagnostic computer).... It was definitely bank 1, cylinders 1-3, so both sensors were changed, but after getting the car back, the fault returned.

Just heard today that all is well and it was an intermittant contact on the 2nd sensor (after the cat) connector pins, causing the fault to display. Mechanic has been excellent and can't wait to get it back tomorrow....£40 for lots of checks and peace of mind....priceless!

cheers 😎👍

[eddiea1]

How many O2/lambda sensors does the IS300 have in total? I need to change mine

[DF-300 Sport]

Hi Eddie, All the part number info is above on the thread...... 4 in total, 2 on each bank of 3 cylinders....one, pre and one post-cat. Fault codes should identify which are faulty. Hope you get it sorted soon.

My O2 sensor issue was resolved after the mechanic changed both on bank one... but the fault still persisted... it turned-out there was a short in the connector too, so all was good once this was diagnosed and fixed. Engine management light now behaving🥳

Cheers and Happy New Year everyone!😎👍

[eddiea1]

On 12/30/2022 at 3:45 PM, DF-300 Sport said:

Hi Eddie, All the part number info is above on the thread...... 4 in total, 2 on each bank of 3 cylinders....one, pre and one post-cat. Fault codes should identify which are faulty. Hope you get it sorted soon.

My O2 sensor issue was resolved after the mechanic changed both on bank one... but the fault still persisted... it turned-out there was a short in the connector too, so all was good once this was diagnosed and fixed. Engine management light now behaving🥳

Cheers and Happy New Year everyone!😎👍

Thanks same to you David!