2 x O2 Sensors gone?

[Anonymous]

Hey guys,

New to the forum after I bought my MR2 on Saturday.

Got her in Edinburgh, and was coming up the road when the Engine Light came on. Took her into the Toyota Dealer in Aberdeen for a diagnostic (£69 for the privilage!), where I was told that not one but two O2 sensors had gone.

Does this seem right to anyone?

£380 in total to get both sensors replaced (not bothered about that, as I bought from a garage and they'll pay it under the warranty!)

One other question, I wasn't wanting to gun her up the road on Saturday, but I had a wee "shot" this morning and she seemed to flat out at just over 4500rpm in second, would this be due to the O2 Sensors?

Cheers,
Ron.

[spit]

Welcome Ron. * I'm moving this into the "Troubleshooting" forum where its better suited and more likely to get a response - Ste*

[Anonymous]

Ron i would get the pre cats checked as they could be the reason for the contamination/failure of the O2's. The main cat may be full and choking the engine from reving. Please read this and act now.  m http://www.mr2roc.org/phpBB2/viewtopic.php?t=11393 m

[Anonymous]

Damn! OK, thanks for that guys, I'll be sure to get the garage to howk out the pre-cats when they're replacing the sensors (that also means the garage I ought it from will pay for that work! ;-))

Help much appreciated!

Ron.

[aaronjb]

A flat spot like that can also be caused by a failing MAF - which might also explain both O2's reading a lean or rich code, for example.

Knowing exactly what code it was reading would be most helpful here  s:) s:)

[Anonymous]

A flat spot like that can also be caused by a failing MAF - which might also explain both O2's reading a lean or rich code, for example.

Knowing exactly what code it was reading would be most helpful here  s:) s:)

Forgive me, but what's a MAF?

I will call the Toyota dealership and ask for the codes....if they'll give me them!

Edit: Just as I thought, they didn't save the codes, apparently!

[SteveJ]

The 4500 rpm flat spot is almost certainly the O2 sensors - Rogue had this problem on his VM180, and when we swapped the O2's the problem cleared.

He was getting bank x too rich IIRC

[kanujunkie]

MAF = Mass Air Flow sensor

its the black lump that sits in the intake just after the air filter box

[spit]

Just as I thought, they didn't save the codes, apparently!

I'd be inclined to persuade a freebie re-read out of them on the basis that they didn't give you the codes. Its not unknown for MrT to advise incorrectly - at least this way you'll know for sure whether its O2 sensors reading out of range or just frazzled O2 heater circuits.

MAF clean is also a good suggestion and an easy DIY job.

[Anonymous]

Wow, OK....trying to take all this in!   s:shock: :shock: s:shock:  

Thanks for the info guys!

How do I go about cleaning the MAF then?

Also, finding it difficult to get a garage to bore out my pre-cat up here, any suggestions?

[spit]

How do I go about cleaning the MAF then?

Unplug it, remove it, clean it carefully with carb cleaner or electrical contact cleaner, replace it.

That's the quick answer.

Longer answers you'll find elsewhere but there's a good article with pics from our counterparts over the pond - Clicky Here

Gutting the precats is not tricky, but best if you can find someone who's done it before and comes recommended. We've a healthy crew of members stretching up past Fife so someone here might come along with advice on that.

One question - I'm assuming your CEL (Check Engine Light) has come back on again....has it?

[Anonymous]

Unplug it, remove it, clean it carefully with carb cleaner or electrical contact cleaner, replace it.

That's the quick answer.

Longer answers you'll find elsewhere but there's a good article with pics from our counterparts over the pond - Clicky Here

Nice one, thanks!

Gutting the precats is not tricky, but best if you can find someone who's done it before and comes recommended. We've a healthy crew of members stretching up past Fife so someone here might come along with advice on that.

If anyone can reccommed a garage in Scotland that would/has done this, that would be brilliant!!

One question - I'm assuming your CEL (Check Engine Light) has come back on again....has it?

AH-HAH! The answer to that is NO! I found that a bit strange myself, however I'm still flatting at just over 4500rpm and finding her stuttery at partial throttle at low revs....

[spit]

If the O2s were completely fubarred the light'd come back either straight away or after a few restarts dependent on the problem. No light suggests they're working and within tolerances at the mo - nice one MrT  s:roll: :roll: s:roll:  

That said, I've had an O2 heater circuit break down and "repair" itself a few times before it gave up completely (confirmed with an ohmeter across the black wires) - but not with 2 O2s simultaneously - nice one MrT  s:roll: :roll: s:roll:  

Get the MAF done. If the light comes back find out what it is. You can get very cheap code-readers/re-setters for UK cars (not J-Spec MR-S) which'll cover their cost twice over on the first readout!

Without scaremongering just yet, keep a close eye on your oil level. And its good to invest in an O2 sensor socket and have a look at your precat tops for peace of mind (ditto for removing the cat and checking the bottoms in the manifold before you take it off and remove them  s:wink: :wink: s:wink:  ).

[Anonymous]

I got warranty with the car from the dealer I bough it from , so they're paying for the repairs, no skin off my...uh...nose.

I'll get the MAF cleaned at the same time I think, get them to pay for that also  s:twisted: :twisted: s:twisted:

[spit]

Forewarned, forearmed and all that.

I guess what I'm saying is that knowing about the condition of the precats - whether or not you choose to remove them - will inform your next move with the dealer. If they're intact you can get on with life. If the tops have broken up you might consider walking away. If the bottoms have dropped they may be blocking the main cat, which'll need replacing, and your dealer will be handing you back a substandard fix if they don't do it.

This is all speculation of course - I'm sure everything will be ticky-boo.

(PS I'm going to shut up on the subject now - there are more knowledgable folk than me kicking about and I'm sure you'd like to hear from them too  s:wink: :wink: s:wink:  )

[Anonymous]

MAF cleaned, Pre-Cat checked (although I think my local garage may be taking them out for me - OR I pay another garage £400 for a FULL S/S system from Manifold back!), sensors replaced.

Just under £500 (garage I bought from is paying!  s:D s:D  ), she's running like a dream....playtime!

[Anonymous]

I spoke too soon.....maybe!

EWL came on again at the weekend, hoping it's nothing serious...


HOWEVER, stuck her into Arnold Clark, Toyota in Aberdeen to get the dignostic run, was supposed to be done before 12...called them at 1215 and was told it would get done at 1245.

Called again at 1330, only to be told that there were no service advisors available, one would call me back....1400 I called again, put on hold for 5 minutes then cut off. Called back again, put on hold for about 3 minutes then was passed from pillar to post....ended up losing the rag and demanded to speak to the manager....car still hasn't been looked at!

Note to self (and any other 2 owners around Aberdeen), drive to chuffing Dundee next time you need to go to a dealer.

Will post results of the diagnostic when I get them.....