o2 sensors / circuit overheat

[Bezza81]

Hello - first post. Apologies if in wrong place! 

I have 07' IS250 with 47k on clock. O2 sensors seem to have gone - bank 1 & 2 requiring replacement. Garage also saying code being thrown up that electrical circuit overheating - is that common when the sensors need replaced? i.e. side effect that will be cured with new sensors? 

Also - lexus want a fortune for the sensors, any recommendations from where else to get them for less ? 

Thanks! 

 

Dave 

[mk_lon]

Hi Dave,

O2 sensors going are pretty common at that age, mine went too. How much does Lexus charge? 

You can buy the HAS branded ones from eurocarparts for around £55 or Denso OEM spec for about £100 from a UK supplier http://www.importcarparts.co.uk/parts-info?id=11426&cat=2070&sub=2080&sec=2083&var=0&dc=&gen=&searchKey=&searchPart=

 'm not sure about the circuit heating up but im sure one of the members on this forum can be of help. 

 

[Bezza81]

Thanks M - that is helpful - Lexus quoting £180 plus vat... so £100 is definitely a lot less! 

[mk_lon]

WOW - I've spotted a few knocking around on eBay for £35 when I was looking...

[johnatg]

Be careful which sensor you are looking at. There are air/fuel ratio sensors (before the cats) and heated oxygen sensors (after the cats) - they are not the same and I think the pre cat ones are more expensive. It's not always obvious from the descriptions on eBay etc.

[Bezza81]

Thanks John I know sensors from Banks 1 & 2 so I think that means pre-cat so maybe more expensive - I'll ask re: where sensors are to be sure 

 

Dave

[johnatg]

Unfortunately both types of sensor are referred to as Bank 1 and Bank 2 (as there's one of each on each bank!)

[Bezza81]

Ha! I think the chances of me getting right sensor are probably 0 - will maybe just get Lexus parts to avoid the inevitable fail! 

[is200 Newbie]

Stick with the recommended sensors - not only will they perform as expected, they will last longer

Bank 1 Sensor 1 and Bank 2 sensor 1 are in the engine bay and can be replaced easy - these are the expensive ones. One is easier to fit than the other but both can be done. If you are replacing one side then its wise to do the other side.

Both sensor 1's are the same - theres no issue in the wire length as it will fit either side (either bank)

You can order these from the USA - I replaced mine last year and purchased them from there. Picture below is of the box - part number shown and its a Denso make.

I have a "walkthrough" on fitting if you plan to do yourself if you want me to post it up on the forum. I did a while back but it disappeared.

[Bezza81]

That is great mate - thanks so much - the walk through would be brilliant to have a look at? 

[mk_lon]

Managed to find it through Google :)

 

[Bezza81]

Superb - thanks for all help guys ! 

 

Dave

[is200 Newbie]

Heres the pictures I originally posted - it really is an easy job. This is for the Bank 2 Sensor 1 side (passenger side which is the trickiest)

PICTURE 1 - The offending sensor removed - this one is the same as Bank 1 Sensor 1 (same fit and wire length and is a direct replacement from the one out of the box in the previous post

PICTURE 2

PICTURE 3

PICTURE 4

PICTURE 5

PICTURE 6

PICTURE 7

PICTURE 8

PICTURE 9

PICTURE 10

PICTURE 11 - I think I dropped a screwdriver at this point !!

PICTURE 12

PICTURE 13

Hope this helps.... Bank 1 Sensor 1 (Drivers side) is a lot easier to remove - I have the pictures but no instruction on how to but if you remove the engine cover (long one down drivers side wing, then you should see the sensor and understand how easy it is to replace.

The sensor removal tool to use is shown below which is available online / eBay etc ...

I am pretty sure, including parts, its a £600 job at a dealer. - Parts if importing from USA will cost around £180 (ish) and the removal tool around £10

[normski2]

Newbie eh ......... bit of a legend methinks.

What a star.

This is exactly what makes this forum so darned good.

[is200 Newbie]

48 minutes ago, normski2 said:

Newbie eh ......... bit of a legend methinks.

What a star.

This is exactly what makes this forum so darned good.

Here to pleeze ... just doing my bit.

By the way - the Battery "suppressor" is shown in picture 3 (not a clear pic tho)

 

Spark plug walkthrough next (then my life is complete) although I think I will have that done with the fuel seal recall ...

[steve2006]

O2 sensors are only accurate when they are hot and once the engine has fully warmed up the heat from the exhaust gasses is sufficient but obviously this is not the case on a cold engine.

To ensure the sensor begins to operate as soon as possible they contain a engine ECU controlled heater element which ensures a fast warm up which is switched off when the engine has warmed up and the exhaust gas temperature provides and maintains the heat.

A common failure on the sensor is due to this heater element failing which in turn flags up a heater related fault code.