O2 Sensor & Eml

[apollo92]

Hello everyone, I am a newbie. The forum is great and I think over the past day or two I have read everything here !

There is definately some really good advice here which is why I am posting the question.

OK. Here goes.......

I have a 2003 MR2 Roadster which has the dreaded engine management light showing. I took the car down to Mr T and they told me it would cost £250 to fix it and replace one of the sensors, found fault code P0141, O2 Sensor 2 in bank 1 required. Even the print out from the diagnostic machine at Mr T's didn't mention the part number so I made several calls to confirm the actual part number required and value of same i.e. £135 plus VAT !

I then found a company on eBay who are selling the actual Toyota original part in america at a reduced cost and had it shipped here. I fitted the part yesterday and guess what ........ I STILL have the stupid engine management light showing. I phoned Mr T yesterday thinking they may have got the part number wrong but they rechecked and after a lot of oo and ahh told me it will need to be plugged into the diagnostic machine to reset and cost £55 (more than the initial £40 to diagnose the fault). I was REALLY very unhappy at this because it sounded like sour grapes because they didn't get the £250 in the first place.

I have checked about everything on the forum yesterday and I just cannot find a definate answer.

I am about to remove all the ECU and EFI fuses and disconnect the neg terminal from the Battery to try to reset the ECU.

I hope this will allow the ECU to reset and turn off the light without any Mr T !!!!

I really think after noticing so many people on the forum with the problem it is a preprogrammed fault which Toyota built into the car when new to make sure we all get ripped off at the dealers a few times more.

I am going to try the reset but if not I am going to Toyota later with the car and will complaint to the manager !

Wish me luck !!!!!

I really appreciate any advice before 2pm today if possible as the car is now booked in (but I will not be paying any more money to Mr T).

Thanks very much. I am really thankful and getting very desperate.

Yours.

Paul.

[Mad-Matt]

Luckily I've never seen this problem, but what you plan to do sounds like it should work. Good luck with the garage!

[cfc1]

Sorry it's a bit late... been working all day.

Disconnecting the Battery will reset the ECU and put the light off, if the problem is cured then it will stay off, if it comes back on then see if any members near you have a code reader that can read the code for you...

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

If there is no-one near you then buy one from eBay...

http://shop.ebay.co.uk/?_from=R40&_trk...-All-Categories

I bought one of these... Item number 290313532882 (shop around I got mine cheaper than that) The live data function can be handy.. but not essential to reset the light and get any codes.

If the same code comes back... more options to cure can be found here or here ;)

[Bob Brown]

I've just received a quote of £215 +VAT (I think) for this work, and I'm not sure what to do about it.

Is this the correct part? http://www.autopartswarehouse.co.uk/product.aspx?ID=197694

I am tempted to do this myself, but I suppose its better that Toyota do it for me... Any quick replies would be great.

Edit: Bugger it, I'll get Toyota to do it while they've got the car. As much as I like working on the car and learning about 'em, I haven't really got the time.

[GIDDLEPIN]

Guys you are paying out £200+ for a £60/70 repair :o , I haven't much time at the moment as I have to get off this bay and go back to the depot but I'll have a look later

[Bob Brown]

Well I haven't asked them to do it for me yet. I may wait and see what I can find. I tried to call them to authorise the work and the receptionist couldn't get through to the service bay - and they needed to order the part in by 11.30, so I wont be able to get that done today anyway now!

So atleast I can consider the options.

[GIDDLEPIN]

Right....

Error code 0120 is for the after cat sensor and while it is a necessary item it isn't as crucial as the pre-cat sensors, in fact, because I have a sports cat and exhaust system on mine this same code keeps appearing even though I have a new sensor in, there is a resistor fix which I will probably do sometime but as it is I will just keep clearing the code once I have checked it.

PLEASE don't keep going to Mr T for your codes read, as Davy said they are only cheap (mine was £20) and you can read/clear codes if necessary.

If you are on a standard exhaust system and need a new sensor, check out THIS thread, open up the page for the new sensors and put your details in, a 2003 Roadster after cat (with the long cable) comes out at about $120 including delivery,this works out to about £73, delivery on mine took about four days and as you see from the thread, fitting is VERY easy.

So save yourself some money and have a go

Les

[Bob Brown]

Right....

Error code 0120 is for the after cat sensor and while it is a necessary item it isn't as crucial as the pre-cat sensors, in fact, because I have a sports cat and exhaust system on mine this same code keeps appearing even though I have a new sensor in, there is a resistor fix which I will probably do sometime but as it is I will just keep clearing the code once I have checked it.

PLEASE don't keep going to Mr T for your codes read, as Davy said they are only cheap (mine was £20) and you can read/clear codes if necessary.

If you are on a standard exhaust system and need a new sensor, check out THIS thread, open up the page for the new sensors and put your details in, a 2003 Roadster after cat (with the long cable) comes out at about $120 including delivery,this works out to about £73, delivery on mine took about four days and as you see from the thread, fitting is VERY easy.

So save yourself some money and have a go

Les

Is there any way to figure out which sensor requires replacement? I haven't got the exact code, but I'll probably buy a code reader considering it wont be any more than getting MrT to do it.

Also, my car was due a service, which is the reason I took it to MrT after my friends professional code reader (very expensive) failed to capture the error code - that or he wasn't trained properly on it - here

Many thanks for the help guys

[cfc1]

Buying a code reader will be more beneficial in the long run, it's a good investment. I have a U381 reader as seen here, it also gives the "live" data and freeze frame so you can see when the code was triggered, as well as giving you the cose it will also give you the description of what the code is referring to... eg P0171 System to Lean (Bank 1), a lot of code readers just display the code leaving you to find out what it means on your own.

The only way to know what sensor it is is to have the code read,

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Les....

Right....

Error code 0120 is for the after cat sensor

Where did you get that from, I was under the impression the a P0120 referred to Throttle Pedal Position Sensor/Switch A Circuit Malfunction... correct me if I'm wrong.

Also.. I see no other mention of that error code in this thread (or bob's other one), have you been trying to multitask again?.. what have you been told about attempting the impossible?

[Bob Brown]

Shame on me, I got Toyota to do it for me. The exchange rate wasn't looking so good on the American parts any more and I didn't know which part I needed to buy without the code reader first. After a few weeks of being too busy I decided to just get it done. £200 flat after I told them that's what they quoted me first time round. I think the invoice listed the sensor as about ~£150. Considering I didn't have the time to do it I don't feel cheated about it.

[cfc1]

Hopefully the problem is solved now, but it could still be a good idea to get a code reader for any future EML's, it will pay for itself the first time the light comes back on as most garages will charge around £40 for reading the code.

[Bob Brown]

Very true, can't really get friends to (try and) read it all the while.

[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