Hi Chaps


New to the forum - have a slight problem.


Took the car (500 Twinair Automatic 2012) for its first MOT yesterday and it failed on Lambda emissions.


The MOT chap told me to take it to Fiat.


It's now booked in for a "1 hour diagnostic test" for £120 following which they may or may not deem to fix it.


And, of course, they wasted little time in gleefully telling me the 3 year warranty has just run out.


My reason for writing is to try and find an alternative way out.


Is this a common problem. Is there a quick fix that works 90% of the time? Is there any other diagnostic solution locally (Enfield, North London) that is not quite so expensive?


Any other advice?


Would really appreciate your help.


Thanks

Ian

isaune said:

Hi Chaps


New to the forum - have a slight problem.


Took the car (500 Twinair Automatic 2012) for its first MOT yesterday and it failed on Lambda emissions.


The MOT chap told me to take it to Fiat.


It's now booked in for a "1 hour diagnostic test" for £120 following which they may or may not deem to fix it.


And, of course, they wasted little time in gleefully telling me the 3 year warranty has just run out.


My reason for writing is to try and find an alternative way out.


Is this a common problem. Is there a quick fix that works 90% of the time? Is there any other diagnostic solution locally (Enfield, North London) that is not quite so expensive?


Any other advice?


Would really appreciate your help.


Thanks

Ian

Click to expand...

Are you crazy? 120? Forget it cancel it immediately.

My recommendation is to pass by a Bosch car service Center who have good diagnostic equipment. A quick search online found motorpointboschcarservice.co.uk HA7 1EP is the post code don't know how close it is to you. Type Bosch car Service in Google and see if you find one close by.


I repeat do not go to the fiat dealer that charged you 120 gbp!!!

As Ahmett, above.

Thanks for the advice chaps.

Just spoke on the phone to a Bosch place a few miles from me.

VERY nice chap.


I told him the readings and he said what HE would do is try a few additives, take it for a long spin, then take advantage of the free re-test.


He said my readings were so close that will probably be enough to get it through.

If not, I'll take it to see him.

One last question - can anyone recommend any good additives? He said I should probably put a couple in. One to clean the sensor, one to clean the injectors etc etc.


So, it's additive advice I need now please chaps.

Thanks


Ian

isaune said:

Thanks for the advice chaps.

Just spoke on the phone to a Bosch place a few miles from me.

VERY nice chap.


I told him the readings and he said what HE would do is try a few additives, take it for a long spin, then take advantage of the free re-test.


He said my readings were so close that will probably be enough to get it through.

If not, I'll take it to see him.

One last question - can anyone recommend any good additives? He said I should probably put a couple in. One to clean the sensor, one to clean the injectors etc etc.


So, it's additive advice I need now please chaps.

Thanks


Ian

Click to expand...

Excellent. Unfortunately I can't help you with additives perhaps ask him?
I am very happy with my local Bosch car service Center, very well trained staff, especially the service manager . You should use them for your regular servicing as well

Reading this with interest, mine is in for an MoT on Tuesday, got me worried now. It came to me with no MoT so who know what delights might be wrong.

I'de be interested to know about any recommended additives.

I always used to use Redex - hope I've got the name right! - it comes in a small green plastic bottle for petrol or black for diesel.

Think its called injector cleaner. Can be found in Tesco motoring section, so is probably widely available. About £5 a go, except when on offer.

Can someone add a bit of accuracy to the above.......?

I used to use Redex years ago, back in the days when we had carbs. I guess its a tried and tested formula. Just thought there might be some super potion that's evolved since then.

They sell it everywhere, even saw it in Wilkinsons yesterday about £4 I think.

isaune said:

... it failed on Lambda emissions.

Click to expand...

That phrase gives me two options.
1. Lambda reading outside parameters
2. Emissions outside parameters.

Either could cause the other, so both readings would be nice to help.

As the lambda sensor is in the exhaust, I'm not sure how any injector cleaner will help, as it will be burnt in the cylinder. However, if the injectors are a bit gummy, a good dose of injector cleaner will do them a lot of good. So go get some Redex injector cleaner and use it.

The lambda sensor could be failing, if so, get a good branded one with the correct plug on it, don't solder the wires as they are working on small voltage changes and any poor connection will screw that up. Some swearing is likely when removing the old one. Soak well in plus gas or other release agent, when cold, then remove when hot as the exhaust should expand more than the sensor.

Bill, I know you have years of experience in the motor trade, so I am treading carefully here, but surely a gummy injector will lead to poor combustion, which will then be picked up by the Lambda sensor?

I know my A Class failed an mot on exhaust emissions some years back, so the garage dropped in some of that injector cleaner, gave the car a brisk run, and all was well.

If I have misunderstood anything here, I'm open to your superior experience correcting my limited knowledge!

snes said:

Bill, I know you have years of experience in the motor trade, so I am treading carefully here, but surely a gummy injector will lead to poor combustion, which will then be picked up by the Lambda sensor?

Click to expand...

Agreed, and this poor combustion might cause the lambda reading to be outside parameters. With the poor combustion results fed to the sensor, the computer will try to adjust, but only has limited range. Ideally we need the actual results of the MOT test to better understand.

Or it could need a new sensor.

Unlikely to need a new cat.

If it has been in London and only bimbled around, a good thrashing may do it some good. Any volunteers?

portland_bill said:

That phrase gives me two options.
1. Lambda reading outside parameters
2. Emissions outside parameters.

Either could cause the other, so both readings would be nice to help.

Click to expand...

Hello Bill

Sorry if not clear. It failed on LAMBDA alone and sailed through the rest of the test.


I don't have the paperwork in front of me but I remember the first test reading ended with "41" and the second test ended with "31" with the target being "30".


I was watching the test - the mechanic had to rev the car really hard (to 4000/5000) to get the numbers to fall but they seemed to stall around the target level and go back up.


He was at it for about 30 mins and must have tried at least half a dozen times. He even rebooted his equipment to see if that might help.


Armed with this (hopefully) improved information, Bill, are you able to refine your advice on what I should do next?

Thanks


Ian

Using the page from my MOT from last week.

Lambda is a voltage check. It should read between 0.970 - 1.030 and fluctuates between these as the oxygen content of the exhaust changes. The ECU uses this voltage to adjust the fuelling to bring the reading into the middle. You figures don't quite match those parameters.

There is a fast idle test, expecting:
CO <= 0.200% Mine was 0.035% This measures correct combustion and fuelling.
HC <= 200ppm Mine was 25ppm This effectively measures unburnt fuel.
Lambda: 0.970 - 1.030 Mine 1.030

Then a normal idle test:
CO <= 0.300% Mine was 0.004% This could be the reading you have trouble with, suggesting an idle fuelling issue, but the full list would be better. You should have been issued with the sheet with the MOT failure.

CO being too high, I think means too rich. Leaking injectors can cause, a clean may sort. It could also mean the Lambda sensor is dying. I think an air leak on the intake would give a low CO reading, rather than high.

Ideally we need the full list.
Then it needs plugging into a diagnostic machine, such as MultiECUScan (MES) to see the readings live to help diagnosis. It is quite likely something simple.

Would have hoped by now someone might have popped up near you with MES. Have you tried the Bosch recommendation? You could download the free MES, but you'll also need the cable and a laptop or netbook to attach to the car.

Hi Bill

I am trying to link to a photo of the emissions failure but can't add a url apparently until I have made 5 posts.

This is number 4.

This is number 5

And hopefully now I can post the urn.



Hi Bill

This is the Emissions failure sheet from the Mot.

Any further advice appreciated.

Please ignore the scribbles.

Thanks

Ian

That will be caused by a leak in the exhaust.
Extra air from leak causes lambda figure to read high due to extra oxygen being measured by gas analyser.
Could even be caused by the drain hole in the rear silencer that 500's have.
Just noticed it is a twin air,some vehicles have a higher than normal lambda figure,this could be one of them. However the gas analyser should load up the manufacturers limits after the initial fail and test to manufacturers figures rather than the first test figures that most cars can meet.

TheCurleyOne said:

That will be caused by a leak in the exhaust.
Extra air from leak causes lambda figure to read high due to extra oxygen being measured by gas analyser.
Could even be caused by the drain hole in the rear silencer that 500's have.
Just noticed it is a twin air,some vehicles have a higher than normal lambda figure,this could be one of them. However the gas analyser should load up the manufacturers limits after the initial fail and test to manufacturers figures rather than the first test figures that most cars can meet.

Click to expand...

So additives in the fuel and blast round the motorway won't help?

Maybe some chewing gum in the drain hole?

Definitely need help here.

Cheers chaps

A good blast before checking the emissions is always a good idea.
Any leak in the exhaust will cause a high lambda reading though.
Not sure if twin air has a rear silencer like the 1.2/1.4's so may not have a drain hole.

Having spent a fair bit of time and money chasing a lambda / ECU / emissions issue with my 2001 Brava 1.2, I would agree completely that an air leak in the exhaust upstream of a sensor will confuse the whole closed-loop control system, as the sensor will (wrongly) think the exhaust mixture is too weak and therefore the ECU will richen up the inlet mixture, and therefore tailpipe emissions will be too rich etc etc.

That's the only fault I would expect on a 3-year old car (i.e. mechanical), rather than a failed OEM sensor or wiring fault.

For the record the best (IMO) catalyst cleaning product is Cataclean, but it should only be needed on a high mileage Cat that has been running rich or wrongly for a while.

On my car I was amazingly able to have the cracked outlet pipe joint of my 155,000 mile Cat welded up and have a clamp replaced to tie it to the gearbox, and it sailed through the MOT emissions test.