RX400h O2 sensors

[Jollyjacktarjack]

Evening folks,

I have an Engine light showing, it indicates the O2 sensors need to be changed. Can anyone signpost me to where I can purchase these items from please? My garage tells me they are on back order but he can’t source them.

Can anyone of you help please? 
 

Thanks

JJTJ 

[Herbie]

You could try http://lexuspartsdirect.co.uk They're a main dealer but sell stuff out a lot less than other dealers.

[Jollyjacktarjack]

Many thanks Herbie, can you confirm there are 3 x O2 sensors on my 2005 RX400h please? 

[Herbie]

1 hour ago, Jollyjacktarjack said:

Many thanks Herbie, can you confirm there are 3 x O2 sensors on my 2005 RX400h please? 

This is from the RX400h workshop manual Jack:

[ColinBarber]

11 hours ago, Jollyjacktarjack said:

Many thanks Herbie, can you confirm there are 3 x O2 sensors on my 2005 RX400h please? 

4 but you should only change the ones that are faulty - possibly the two upstream sensors together as they could fail within a short time frame of each other.

 

What error code(s) do you have, did the garage tell you?

[Jollyjacktarjack]

Many thanks Herbie and Colin B!  I read the following on my VeePak OBD:

Car Scanner ELM OBD2

DTC report

Selected brand: Lexus

============1==============

P0037

Raw code: 0037

ECU: Engine control unit

Status: Confirmed

OBDII: Heated oxygen sensor (HO2S) 2, bank 1, heater control - circuit low

Lexus: Oxygen Sensor Heater Circuit Low Input (Bank 1, Sensor 2)

============2==============

P0037

Raw code: 0037

ECU: Engine control unit #1

Status: Confirmed

OBDII: Heated oxygen sensor (HO2S) 2, bank 1, heater control - circuit low

Lexus: Oxygen Sensor Heater Circuit Low Input (Bank 1, Sensor 2)

Still unsure which sensor this actually relates to please?

Thanks,

JJTJ

[Jollyjacktarjack]

Evening Folks,

Update on the issue below - changed the O2 sensor (sensor (HO2S) 2, bank 1) and the car ran great for 18 months. The same code reappeared in Dec 23, changed the same sensor and it cleared for a week, sent that sensor back and bought another, ran great again for 1 month.  Today the following popped up:

P0138, P3190, P3193 and P0A0F

The car ran rough for a bit, stopped and restarted. Continued home and all appeared to be running OK, the Check Hybrid System lights remained illuminated though.  Any thoughts please folks MAF, another sensor change,Hybrid Battery starting to fail...?

Thanks JJTJ

  

[ColinBarber]

Certainly worth cleaning the MAF as a starting point. 
 

 

 

[Jollyjacktarjack]

Thanks Colin, assume I can use carb cleaner please?

 

[Jollyjacktarjack]

Update Folks,

MAF cleaned, as well as the air filter.  Car driven this morning and all was well until the car had warmed up, the old symptoms of the car appeared, ie a selection of beeps and warnings and being forced to limp home on the hybrid Battery (the engine does restart if you switch on and off though) above codes are still present as well as some new ones - C1259,C1310.

Anymore thoughts before I think me and my trusty Lexus have to part ways please?

Thanks,

JJTJ

[ColinBarber]

This all seems engine related. It really needs a proper diagnosis by looking at all the sensor data, especially when it goes into a fault condition - otherwise you will be guessing. Worth checking that state of all the vacuum hoses in case they are perishing and open up when they get warm. It could be related to the MAF and O2 sensors, but you really want to narrow down what the problem is rather than throwing money at it by replacing parts that aren't faulty.

On 1/10/2024 at 8:27 PM, Jollyjacktarjack said:

Hybrid battery starting to fail

I don't think so. The faults related to hybrid are because the engine is failing to start - the same as those two new codes, they typically appear when other problems exist rather than being the root cause themselves. Worth checking you don't have water ingress in your boot though, as it is a common issue on older 400h vehicles.

[Jollyjacktarjack]

Thanks for the response Colin, much obliged.  I do get water ingress, common with this model.  In wet weather it gets a cover placed over it!

To the vacuum hoses, assume these are the ones to/from the air filter area please?

Thanks,

JJTJ