Bank 1 Sensor 2

[1bloke1dog1mr2]

Just bought myself an OBD2 reader for the CEL. Comes up with bank 1 sensor 2, which is the after cat. I knew it wouldn't be the pre cat as I've just changed both, although originally they were the problem.

Question is, do I;

1: Replace it?

2: Not worry about it?

3: Worry about the pre-cat failure (checked it while doing the pre-cat sensors and looked fine, also passed emissions in the MOT in Nov)?

4: Wire it so it bypasses the sensor?

..any suggestions Doctor?

[GIDDLEPIN]

1: Yes

2: If it's replaced you won't have to worry ;)

3:Check your oil religiously, my pre-cats are still in but that doesn't mean to say they won't fail like anything else on the car could, I have enough grey hairs without worrying about what might go wrong :D )

4: see 1

Faulty after cat sensors are not as likely to cause the ECU to dump gallons of fuel in your engine because it senses it running lean (this would not be good :o ), but it is still a sensor at the end of the day and even by-passing could throw up a CEL on something else related to it.

Les

[curriedb]

Les's advice is spot on! What a wise old sage you are Les (less of the old says Les!!)

A sensor's role is about alerting you to a potential problem - before it leads to an expensive component failure. They are sensitive little souls and are a darned nuisance when they give a false alarm. Many F1 drivers and Shuttle pilots share your frustrations!! However, without them your systems are not being monitored effectively.

Your new code scanner has saved you wasting money paying Mr T for a diagnostics check. So spend it, instead, on installing a new sensor. Then - HOPEFULLY - you can relax at last!

Happy motoring

Dave

[1bloke1dog1mr2]

Thanks Les & Dave , well if I'm going to change one sensor I may as well change them all! I have noticed an improvement in mpg with the new sensors in. As with the precat problem, I've got no symptoms and the oil doesn't go down from one service to the next since I've owned the car. As you say Les, it's not worth the grey hairs!!

Automedics here I come...... :D

[1bloke1dog1mr2]

Just looked at the post-cat sensor and noticed it has 4 wires (2 black 1 blue 1 white) but the replacement sensor from automedicsupply only has 2 wires.

Is it suitable?

Also looks like I'll be taking the rear bumper off

[GIDDLEPIN]

2 wires.......No :(

Should have got it from HERE

The universal which is correct with the 4 wires, just needs joining to the wires on the original plug (everything is supplied for this) They cost $49.90 + postage which would work out to a total price of about £30, shipping takes about 5 days so it isn't that bad

As far as removing the rear bumper........Noooooo!

If I can take this picture by just pointing it under the N/S/R of the car, it would be a piece of wee-wee to remove and replace

[1bloke1dog1mr2]

Don't panic!!! ;)

I haven't ordered it yet, but Automedicsupply.com is where I got my last 2 sensors from (took 10 days for me). If you go through the menu and get to the MR2/MRS sensor, you'll notice that the after cat sensors they sell only have two wires.

I know that the after cat sensor for the roadster is slightly longer than the pre cat sensors so I don't want to get the wrong one!

At least I don't have to remove the bumper though

[GIDDLEPIN]

Do you mean this diagram?

The pictures they use are all the same but the information on the left is what counts and it specifies 4 wires

[1bloke1dog1mr2]

I'm REALLY confused!!!!!

When I look up the after cat sensors for the MR2, the page looks exactly like that, but the sensors have 2 wires not 4. My model is 2000 and that would be the only difference between our searches! When I look up Celica, it has the one you've screen grabbed. Shall I go that instead then?

[GIDDLEPIN]

Woops!

Mine's a 2002 and I looked at yours ....you are right it is a 2 wire...My bad

[1bloke1dog1mr2]

Phew, thought I was going mad. What's the best plan? Mine does have 4 wires, did the roadster change much in 2 years?

[GIDDLEPIN]

I've just remembered, the details for the sensors are for the MRs spyder which is the overseas models (to us). Our emissions were more stringent than theirs so I am almost certain the type with the four wires like mine is the one you want

Les

[1bloke1dog1mr2]

That's what I thought, but it's always good to get a second opinion (well third if you include my Hubby who is getting totally fed-up with my car!) Makes sense though.

Cheers Les.

[curriedb]

GENERAL LAMBDA INFORMATION

For anyone who can't sleep try reading the nurd's guide to Lambda sensors :)

http://www.picotech.com/auto/lambda_sensor.html

Here's an extract from the,excellent, comprehensive article: "...A lambda sensor's normal life span is 30,000 to 50,000 miles. But the sensor may fail prematurely if it becomes clogged with carbon, or is contaminated by lead from leaded petrol or silicone from an antifreeze leak or from silicone sealer.

As the sensor ages, it becomes sluggish. Eventually it produces an unchanging signal or no signal at all. When this happens, the Check Engine Light may come on, and the engine may experience drivability problems caused by an overly rich fuel condition. Poor fuel economy, elevated CO and HC emissions, poor idle, and/or hesitation during acceleration are typical complaints..." (Extract Courtesy of Picotech.com)

Also see Common Faults Visual at: http://www.lambdasensor.com/main/mfaults.htm

and if you still haven't satisfied your appetite see: http://www.volvoclub.org.uk/faq/EngineSens...eandDiagnostics

I believe Les - as usual - has found the best priced supplier of oxygen sensors (address posted earlier in this thread) but there are UK sites too. If you can't wait for the US Postal Service try:

http://www.probedistributors.co.uk/Product...p=LambdaSensors

Their website list a universal (front?) sensor for the MR2 (see comp. chart car listed between Peugeot 607 2.2 and VW Bora!! Don't ask me why!!) at a reasonable price.

Please note I have no personal experience of this company's service.

Hope members find this info of use

Dave

[1bloke1dog1mr2]

That's great info Dave, cheers mate!

[curriedb]

FOR INFO

Draper do a cheap sensor tester (around £12). Please note that the unit will only test sensors with Zirconia elements (testers that will also check titanium sensors appear to retail around £120 ish)...

Retailers selling these units include:

http://www.shop-com.co.uk/op/~Draper_LAMBD...r-prod-23047434

http://www.abbeypowertools.co.uk/car-servi...0001-68283.aspx

http://www.mccormicktools.com/category.php?id=1144928308

Can't add anymore as I've no experience of using such testers.

[1bloke1dog1mr2]

Well what a job! Got the 4 wire post-cat sensor through a few days ago and we decided to tackle it yesterday.

It's the toughest out of the 3 on the roadster that's for sure. In the end (after an hour of plus gas and brute force) we decided to remove the rear bumper - and what a difference it made.

Because of the angle of the sensor, we couldn't get the sensor socket straight enough for leverage on it due to the exhaust being in the way, so every time the socket was turning, it was rubbing off the corners of the sensor :o . So once the bumper was off, we could use a normal 22mm socket (which incidentally was a much tighter fit). This involved cutting the actual sensor in half, slotting on the socket and getting it loose.

Well the easy bit was rewiring and putting the new sensor in then re assembling the bumper. A good job done.

All three sensors changed, Hubby's glad we don't need to do that job again in a hurry!!! ;)

[GIDDLEPIN]

Glad you sorted it and well done for the perseverance in tackling the job

I would probably have chopped the wires on the old one and slotted a cranked ring spanner on the sensor as a second option before removing the bumper ;) It doesn't matter how it was done in the end though, a successful outcome is always satisfying

(Where is the picture record for the file? :P (Kidding ))

Les

[1bloke1dog1mr2]

Unfortunately the sensor was too wide to get any spanner over it, because I suggested that and got a few blue words back!

Only piccies I have is of the whole rear bumper off...

...and half a sensor, which was suprisingly easy to saw through!

But if anyone wants any helpful suggestions as to changing O2 sensors I'm here!

All of this wouldn't have been possible without you helpful lot at TOC!

[curriedb]

It's raining here in the Dales. Not a day to go off with the hood down...

Anyway, well done from me too! What a way to spend your Bank Holiday...but it's a job well done.

That sensor certainly bears the scars of a part that didn't want to be released without a fight! I'm sure others will find you info useful.

Were you able to rewire the unit straight into the existing wiring loom connector or did you need to make a mechanical or solder joint on each of the 4 cables? Would be helpful to know...

Regards

Dave C

ps Now I don't want to start "a domestic" but picking up on Les's point (having looked at the pic he supplied at the top of this thread) I can't quite understand why a 22mm cranked spanner wouldn't have fitted over the sensor. I can see it's too long for a standard socket. And I know there are special deep - slotted - sockets manufactured for removing sensors without cutting off the connector block...but if you are cutting the wires then wouldn't a ring spanner suffice? I'm just seeking clarification as a DIY enthusiast...I'm no mechanic!!

[1bloke1dog1mr2]

The sensor sits quite deep (more so than the two manifold ones) so the spanner wouldn't sit on the sensor straight enough and it is a tight fit under there with the exhaust pipe sitting so close. As the sensor had to come out anyway it was worth cutting it. We have got the proper 22mm sensor socket that did the job for the other 2 but this one was tougher and as you can see from the pic it was just smoothing off the edges. It didn't seem to fit as well as a normal 22mm socket or spanner.

As far as rewiring goes I find the crimps provided with the sensor do a fine job of joining the wires. I did consider soldering but once you secure the crimps with a firm hand and finish off with the heat shrink tubes, they are very secure and it's only a 2 minute job.

I think you can buy the sensors that already have the plug attached, but the 3rd sensor has such a long wire it's not worth the hassle of feeding the new wire round the bodywork.

2 days on... NO CEL :D :D :D

[curriedb]

Many thanks for the clarification. Most useful and much appreciated.

Pleased to learn the job's done the trick...no light on...and even if you've skinned your knuckles getting "the swine" out you can now pat yourselves on the back for having saved ££££ from not having to rely on a Toyota garage!!

Happy motoring

Dave

[curriedb]

Interesting article on "Check Engine" light.

http://www.mobil1.com/USA-English/MotorOil...ngine_Light.htm