Surely an air leak between the centre and back box won't affect the lambda which is in the dp?

Sorry. Should have read the post properly. The air leak won't affect the actual sensor reading just the reading at the tailpipe.

[Edited by taylor - 7/1/2003 7:18:58 AM]

 

Disagree.. when MAF is failing it will stall or in extreme cases fail to start... due to it changing mixture.

I think the ECU is not seeing the true Lambda reading as the sensor is faulty so it is currently running rich.

Part no. L300.. halfords code 180398 £25

JGM

[Edited by Jolly Green Monster - 7/1/2003 11:26:51 PM]

 

Car has just failed its mot for emissions.

Was fully decatted and the centre cat was put back in but it still failed on the Lamba sensor reading (?) .1 out. The car was warmed up!. Now to get my MOT I will need to put the downpipe on but before I do that I wondered if there was any other things to try and then retest

I have got a tek 2.5 would putting the AE802 back on help .. would octane booster help.

Any suggestions? Not worried about the putting the dp on, just looking for simpler and cheaper.

Help ?

Dave.

 

double cat cc if you can find one

dave

 

How would that affect the lamba reading that is in the downpipe ?

[Edited by DemonDave - 6/30/2003 6:24:06 PM]

 

PS ... anybody know of a double cat in the midlands area

 

We have about 15 cats down our road DD they sleep on our cars

 

Putting the 802 back in certainly will help the emissions.

As for the cats, I've got one you can have. Does it matter if it's complete though? Some of it's still in my wheel arch, and I'm sure there's more still on the road...

 

Erm; lambda reading I think might usually mean that the lambda sensor's going/gone to poo?

 

This is not a fix, but will help lower the test results...
Get the cat as hot as poss and try again. with only the center cat fitted this will take alittle longer than normal. A good 20+ min run is needed, just before the test.

 

Dave, I don't see how putting the downpipe back will help either, the lambda is before the cat in the downpipe, so how could even that help???

 

Ok everyone .. thnx for the advice ...

Tomorrow I will try a long run before the check .. swapped back to the AE802 which also is therefore reset. If that doesn't work then I will ask for them to try a new lamda sensor.

Ta.

Dave.

 

Hold on a minute.. the lambda sensor is before the cats on the car but the MOT place put their own sensor in the tail pipe.. cat / lambda sensor location has no effect.

Often the Lambda reading is increased due to air entering the exhaust system.. make sure you have no leaks.. mine was high on lambda reading due to a leak between centre and backbox..

JGM

 

Good call ... I well get them to check that.

Ta

Dave.

 

Ok .... still failed

No air leak.
AE802 back on

CO2 went down but lamda reading went up.

Looks like front pipe will need to go back on tomorrow

Unless anybody has any other suggestions or a double cat

Dave.

 

MAF sensor as per my email I reckon Dave.

All,

I had the same problem and ended up scraping through somehow I bought a TEK2 shortly after and after fitting, my idle went haywire. Seems the MAF was shot and had been for some time, only uncovered by an ECU reset. Pete Croney advised it was the MAF. Went to PE and they fitted a new one, problem solved!

Try actually resetting the ECU, not sure if this will happen by removing it? If not, try a new lambda sensor.

As Ron said, not sure the DP will help, as you passed all the other ones. If there's deffo no air leak, you have some form of sensor fault.

MB

 

Bite the bullet and have a ride to Scoobysport to have a go with their double centre

 

Alternatively find a friendly MOT centre who accidently runs the wrong car through the emission test. I've heard thats what some people allegedly do

 

Don't get distracted by just passing the MOT when there could be a fault with the car..

£25 for a Lambda sensor from Halfords...

You can reduce the Lambda in the exhaust gas but running at a slightly higher tickover.. if the mot place is worth anything they may have tried this.. foot on throttle to 2000rpm and hold for a minute and the lambda reading should come down.. and pass..

Still need to check there is not a problem with the car though..

 

my car failed MOT on emmisions 2 weeks ago (99T uk turbo) as they were to high. Replaced lambda sensor myself(easy job) with universal type. Car passed easily

Don't think it will be MAF as this would make car run lean (correct me if im wrong)

hope this helps anyway

 

MAF will make no difference at idle.
Dodgy lambda could make it run lean at idle, although it's more common for it to go rich if it's failing. The lambda sensor, that is

 

Cheers chaps ... I will get them to change the lamba and recheck for air leaks again before the dp comes off.

Dave.

 

JGM - Agreed. I though it wouldnt make a difference, after an email with Pete Croney I changed my mind, and the MAF. No probs.

Dave - you get it sorted?

MB

 

Fun this diagonosing cars on the net

Dave are you at the meet on Thursday?

Simon

 

ECU or octane booster will make no difference.

Either lambda or MAF could cause a failure.

If the MAF is out the ECU may be in the wrong part of the map to be able to correct to closed loop.

Go for the lambda first then the MAF if that fails.

Can you tell us the lambda value, and the other data from the tests please?

 

Just to add, John helped me on solving mine too!

MB

 

ok i 've just sold my mot station so can now say what i want

lambda reading on mot is there to check that there are no fiddles being done to get a low emmissions figure, i.e. a hole in exhaust, it works by basically calculating a ratio of certain gasses in the exhaust. its quite possible for the lambda ratio to be ok yet the emmisions fail due to a lamda sensor failure or other problem. you can usuallly tell if its a hole in exhaust (and it only takes a very small leak on some cars, the sort of leak you get if you've just changed a part of your exhaust (cat refit ?) and not quite got it to seal, you may not even hear it) as the lamdda ratio will come better when you take revs up higher, also they often close up and seal when really warm. the hc part of the mot test is basically there to stop cheating aswell as it was mainly designed to stop you bringing in your mega tuned up rally escort running as rich as **** and pulling a plug lead off to lower co reading

if its a friendly mot station they may well test the "wrong" car or they could find that they can't connect the rpm pick up to the car and so have to "check and control" the rpm off the cars rev counter and of course "mistakes" can happen which coincidently make the emmisions passable

 

ive just had mine done....when it came to the fabled test....low and behold the car turned into a vauxhall corsa........passed with flying colours......ehheheeh


find a friendly garage.......they still did a top notch MOT, becuase i would definetly NOT drive a dangerous car.....


all the best


jay

 

I agree with Nom. Lambda fail lean, so the ecu adds fuel and the car runs rich. When they are knackered, they run very rich. On boost fuelling is not affected.

It sounds like your lambda is working OK but just getting a bit tired. A new one should sort it.

 

How about trying an Ecotek device....

The device helps cure flat spots in acceleration, helps increase MPG and all helps in lowering emissions. If you take a look at their web site a lot of people have installed one of these to get their car through its MOT.

Below is a clip from their web site:

The tests conducted by REVS magazine show improved performance and acceleration and, most significantly, a 64% reduction in Carbon Monoxide (CO) and a 13% reduction in Carbon Dioxide (CO2) under MoT test conditions.

The device is £48.99 Inc VAT & P&P. It carries a 30 day money back grantee and a 2 year warranty. So if it don’t work you can send it back!

They also have a forum on their website which is really good. The two guys who look after it will be more then happy to answer your questions.

Check them out at http://www.ecotekplc.com/

I fitted mine on Saturday, only took 10 mins! Now I’m ready to get my decat fitted!!!! The device is very well built!

Cheers ;-)
The device is £48.99 inc VAT & P&P. It carries a 30 day money back grantuee and a 2 year warranty.

They also have a forum on their website which is really good. The two guys who look after it will be more then happy to answer your questions.

Check them out at http://www.ecotekplc.com/

I fitted mine in saturday, only took 10 mins! Now im ready for my decat!!!!

Cheers ;-)