Possible failed lambda sensor

[Diz]

Hi folks,

 

Well, I was driving home and a wee light that looked a lot to me like an alternator came on, so I stopped into Farmers to get it checked out. Before going in I checked the handbook and it said 'Failed indicator light', so I took that literally and checked all my indicators were working, even the brake lights <sigh>. I wish I wasn't such a diddy when it comes to cars, I suppose at least the guys in the garage get to point at me and laugh   

 

One of the guys came out with the engine management testing device which said 'failed lambda sensor'. He cleared it but it came back on. I wonder if any of you can answer my questions.

 

The last three times I went to fill up they only had regular unleaded and this beastie is meant to run on super unleaded. Could that affect the sensor in any way?

 

Last year I had to use some of that stuff you put in the fuel tank to clean the engine to get through the MOT as the lambda reading was too high. It worked a treat. I put some more in tonight and will report back on this.

 

Finally, if it really has failed (the guy said it might clear of its own accord but I wouldn't bank on it) is it worth trying to pick up a second hand one, and if so is the sensor specific to the WR1? If not any ideas on where best to pick one up?

 

Cheers,

Diz

[stants]

I wouldn't bother with a cheap one or 2nd hand as they are usually rubbish and you end up buying twice, best place to get a genuine subaru one is www.importcarparts.co.uk not cheap but guaranteed to do the job, have you had a look at getting a cheap diagnostic scanner from eBay and an app for your phone ? Will enable you to read and clear codes yourself and save some pennies but not having a garage look at it

[Diz]

I know the guys at the garage so they don't charge me for the diagnostic or for helping out with other bits and pieces, which is sweet. I must have some inbuilt charm as even my eyelashes are greying ;-)

 

Good to know re the second hand sensor issue, I'll check that out - thanks very much.

[Fastboy67]

I had the light come on as well and purchased said lambda sensor from scoobyworld and a scan tool to clear the fault code once the new sensor was fitted. Both reasonably priced and delivered quickly. Can be a wee bit tricky taking the old one out nothing that a squirt of wd40 didn't cure just don't get it on the new sensor though.

[Diz]

Checked www.importcarparts.co.uk and correct, it is pricey. Also have a front and rear lambda sensor. I could do without buying both, would the engine management test show up which one is faulty?

[stants]

Yes should tell you which one is duff, it's most probably the upstream one as that's the one that's gets the hottest, don't hold me to it though

[Gozling2]

Best thing to do is get a tray of Doughnuts for the helpful guys you know at the garage, make them a cup of tea while they check out the lambda sensors function for you, small cost to you, however a big saving in the pocket area re which sensor is faulty, easy to check on a reader in situe and running.

[Dino]

9/10 it will be the front lambda sensor. Once the EML light comes on then it's pretty well had it. You can't clean it either so a new one is needed.

If you have a engine fault code reader, then you may be able to see the O2 lambda reading live data and it will show you a value to check against. If its too high, then its a replaceable item.

Also, to remove the lambda sensor, you're better off spraying some plus gas into the bolt joint to the exhaust and letting it soak in for 30 mins or so. This will make it much easier to loosen off the nut.

[Fastboy67]

As Dino says you need to give it a good soak in penetrating fluid and use a ring spanner to remove so it lessens the chances of rounding the nut. I started with an open ended spanner but it started to round so hunted for a ring spanner to finish the job. I took the heat shield off and loosened the inner wheel arch plastics off to gain access.