MOT failure and Cats
#1
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]
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]
#2
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MAF will make no difference at idle
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]
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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.
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.
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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...
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...
#10
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.
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.
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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.
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.
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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
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
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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.
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.
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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
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
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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..
£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..
#20
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
Don't think it will be MAF as this would make car run lean (correct me if im wrong)
hope this helps anyway
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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
Dave - you get it sorted?
MB
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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 are you at the meet on Thursday?
Simon
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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?
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?
#27
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
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
#28
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
find a friendly garage.......they still did a top notch MOT, becuase i would definetly NOT drive a dangerous car.....
all the best
jay
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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.
It sounds like your lambda is working OK but just getting a bit tired. A new one should sort it.
#30
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 ;-)
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 ;-)