O2 Sensor Replacement

[GIDDLEPIN]

Since returning from our Corfu trip a CEL decided to make itself known, the code showed it to be one of the O2 sensors.

Not being one to mess about I decided to replace all three, (2 pre-cat, 1 after cat) also being of sound mind and body (including my wallet) and having bought sensors previously from .HERE without any problems, I undertook this mammoth task myself (with the assistance of my friend Mike)

As usual I took a picture record of the procedure and I hope it will be of help to those of you who want to save a shed load of money on what is a relatively easy job.

The parts were ordered on line Tuesday 17th June and arrived the morning of Friday 20th June.

I opted for the 250-24200 Walker Universals at $49.90 each with shipping at $25.00 the total cost was $174.70 with no duty to pay giving a price in sterling of £88.50

The last price quoted by Mr T to replace one sensor was £215

Total time to replace all three sensors (including taking pictures) approx 30 minutes

One important detail I can report and that is after removing the top sensors my pre-cats are still in perfect condition after over six years and 65000 miles.

The sensors arrive well packaged with all necessary fittings

This socket is absolutely essential for removal and replacement

Pre-cat sensors (sprayed with release oil an hour before)

Removing is easy with the right tools

The old and the new

Wires crimped to the original plug

Heat shrink covers

After cat sensor removed easily from underneath the nearside rear (even with my quad pipes in the way)

Copper grease (supplied) was used when replacing the sensors and all appears to be working well

Hope this has helped to dispel some of the terrors of DIY maintenance ;)

Les

[1bloke1dog1mr2]

It all comes flooding back! Good pics Les, well worth sticking in the hints & tips

I found that third sensor a real bugger to remove due to lack of space, ended up removing the rear bumper to get leverage. You did well!!

[curriedb]

Thanks Les...appreciate your thoughtfulness in taking the pics - so that other members can benefit from your experience! Glad to know all went OK.

DC :)

[Joan.A]

Thanks for crucial information Les. I think I've exhausted the other possibilities ( cleaned MAF sensor, checked 15 amp fuses and checked alternator connections - light goes out for 50 miles) So, I've just ordered set of sensors - same as yours - and have two questions for you. What is that socket and where can I get one? Which release oil do you use?

Many thanks, Joan

[GIDDLEPIN]

Thanks for crucial information Les. I think I've exhausted the other possibilities ( cleaned MAF sensor, checked 15 amp fuses and checked alternator connections - light goes out for 50 miles) So, I've just ordered set of sensors - same as yours - and have two questions for you. What is that socket and where can I get one? Which release oil do you use?

Many thanks, Joan

Hi Joan and welcome to the club

I borrowed the socket from my friend but you can get them without any problem at a reasonable price from various places Like HERE

The only release oil I used was WD40 ;)

Hope everything goes well and let us know how it goes

Les

[TK41]

Thanks for crucial information Les. I think I've exhausted the other possibilities ( cleaned MAF sensor, checked 15 amp fuses and checked alternator connections - light goes out for 50 miles) So, I've just ordered set of sensors - same as yours - and have two questions for you. What is that socket and where can I get one? Which release oil do you use?

Many thanks, Joan

Hi There, started going down the same path as you, done the MAF - no better, what is the 15A fuse labelled up as on the cover lid and where are the alternator connections ( besides the obvious ).

Thanks in advance.

[Red Adair]

Hi there

Another girly new member here with a sensor query !

Have identified pre-cat sensor as one to replace and viewed your instructions.

Firstly, well done for taking the time to take some pictures for us novices to view....

However, quick query regarding the socket - does this come with the sensor ? or am I asking too much ??

is it a specific socket or should somthing in a normal socket set do the job ?

tks

Red

[curriedb]

Welcome Red. Suggest you buy the special slotted socket - which allows you to slip it over the sensor's connecting wires - especially if you want to fit an original spec unit...which will come with a wiring harness connector pre-fitted. They are not expensive.

Here's an example of one at a good price:

http://cgi.ebay.co.uk/DRAPER-22MM-3-8-LAMB...id=p3286.c0.m14

I should point out that I have not bought from this seller. A quick search will reveal plenty of other listings...

[Woolymammoth]

If you look on the Link that Les posted above for the sensors you can buy the socket as well for $9.95, the universal sensor is now $51.91 but still the cheapest around. Good work Les mine have just gone but will now be doing it myself. :D

[Woolymammoth]

Hi Guys,

I thought i would share this with you as a lot of these threads are all over the place and not clear on what to do, this is the cheapest fix i have come up with for your engine management light being on solid not flashing and the dreaded o2 sensor replacement.

1 : Firstly try cleaning your MAF sensor with a tin of carb spray see the link under technical information hints and tips....MAF sensor cleaning will cost you nothing..

http://toyotaownersclub.com/forums/index.php?showtopic=63346

2: If that does not work check all your fuses to see if any have blown.

3: If that does not work you need the error code to find out which of the 3 oxygen sensors have possibly gone, there are 2x pre cat, 1x post cat.

Now there are 4 ways of doing this, Mr T or a garage can do a diagnostics which will cost you about £40, or if you know somebody with a handheld diagnostics machine that can do it, or there are some guys on this site that offer to read your error code for free they have a hand held diagnostic machine you can use just follow this link:

http://toyotaownersclub.com/forums/index.php?showtopic=85601

or you buy one off eBay an OBD2 reader for about £25 , the 16 pin diagnostics connection is under the drivers side dashboard at knee height, or the way i done it:

If you are covered by a breakdown service, i am with the RAC, phone them and say your engine management light has come on i have pulled over to the side of the road and need assistance, i need your guy to come out and tell me if it is safe to drive my car to a garage, insist on them coming out.

They did come out for me and he pluged his diagnostic machine in and give me the error code for free.

The error codes i have found on these forums are :

Po141 or 0120 O2 sensor heater circuit malfunction bank 1 sensor 2 ( post cat sensor under the bumper )

Po135 O2 sensor heater circuit malfunction bank 1 sensor 1 (right hand side of manifold pre cat sensor)

bank 2 sensor 1 (left hand side of manifold pre cat sensor)

4: So now you can either go to Mr T or a garage which will charge you about £250 to replace one sensor or you can purchase the O2 sensors in the UK, i have just got a price they are roughly £80 each and they are the cheapest you can get or:

Get them in America copy and paste this link in your browser

http://www.automedicsupply.com/index.php?&...&height=768

You can get your oxygen sensors and the socket you need to get them out and delivery for half the price of any where in the UK seriously!!! so all 3 sensors plus the socket costs you about £120.

5: Then you can fit them yourself with the pictorial guide Les has made in technical information hints and tips oxygen sensor replacement :

http://toyotaownersclub.com/forums/index.php?showtopic=83024

6: Lastly after you have fitted your sensors you need to reset your engine management light on the dashboard, instead of taking it to Mr T who will charge you £50 for the privilage, simply disconnect your Battery for 10 minutes and it will re set your ECU

and if you have cured the problem the engine management light will stay out.

I hope this will help a few people, as this site has helped me save a fortune, Les you are a Mr2 God!

Neal

[ENIGS^^]

may i know where the after-cat o2 sensor located? today i went go down the underneath to find it but i cant find it,i search all around from the other side of the header to downpipe to exhaust..didnt see any...

[ENIGS^^]

may i know where the after-cat o2 sensor located? today i went go down the underneath to find it but i cant find it,i search all around from the other side of the header to downpipe to exhaust..didnt see any...i just see the 2 precat sensor..anyone can point me where is it?thanks alot

[wabbitkilla]

As per your other thread Enigs, on a Japspec MR-S import you don't have a thrid O2 sensor ;)

Saves a bit of cah eh!