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what a nightmare, had the 2nd mot done today, failed on the emissions, ive already spent more than i wanted on the car the now the big question is what to do next. I'm sure its 1 of 3 things. its either the cracked manifold (the crack is before the lambda sensor so if its letting air in/out it could be screwing with the lambda readings), the cats or the lambda sensor, the MOT dude suggested changing the lambda first, but i don't wanna have to play trial and error as 1) the car was meant to be on the road months ago and 2) im going on holiday in a few weeks so dont have spare cash to throw at it!.

Does anyone know anyway that i could test each part to try to diagnose / rule out whats causing the problem? also the car has been sitting for 18 months before i got it so long run would prob help but i cant take it anywhere until its got an MOT. bit of a catch 22 really :(

any help would be grately appreciated :Cool2:
 

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A faulty lambda should produce a fault code, but you never know. If you have a reasonably good voltmeter you can check the function of the lambdas (guess you have one for each bank). You need a connector to connect to the lambda signal wireing without taking out the plug. Something like this:
http://www.biltema.no/products/product.asp?iSecId=464&iItemId=78436
The signal should fluctuate between ~0.1 and ~0.9 V at a rate of approx. 1Hz. It should never stay at a voltage value over time. If it does, it is ready to be replaced.

Are the emissions slightly high, or way out? If they're only slightly high, a commonly used trick is to add some ethanol to the fuel (guess E85 is difficult to get in UK) and of course drive like you stole it just prior to MOT to make sure the cat is hot enough.

-Magnus-
 

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you can use chemical metal as a temp fix to test the crack in the manifold and this would throw the emissions. there is something you can get from the hairdressers to go in the tank but i cant remember what it is. personally i'd chem metal the crack first then get a gas test on the exhaust (most places will do it for free or £5).
 

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I thought the picture was self-explaining:) Quick'n dirty translation:

Branching contact.
For quick branching. Swift and simple connection to a cable. Strips insulation and provide electrical contact in one movement. Cable size 1.5-2.5 mm^2. 5pcs.

I didn't expect the guy to buy it from norway, but I guess similar items are sold in the UK.

-Magnus-
 

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Vivaro 2.0 CDTI Sportive, Mazda 6 Skyactiv
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My omega was making avery loud noise from two large cracks in the passenger side mainifold, also the gasket had gone between the manifold and the downpipe, yet the emmissions were perfect, the bloke who mot'd the car could not beleive it!
 

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there is something you can get from the hairdressers to go in the tank
That will be ACETONE then, do a search on here if you need convincing, make sure its 99% pure and not purfumed, 90ml per full tank of fuel at every fill up.

that will sort your emmisons, i swear by the stuff.
 

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That will be ACETONE then, do a search on here if you need convincing, make sure its 99% pure and not purfumed, 90ml per full tank of fuel at every fill up.

that will sort your emmisons, i swear by the stuff.
Acetone eh? does it improve performance and economy at all? Wonder what would happen if you used it in larger quantities...
 

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Acetone used in larger quantities will actually knock the mpg down , use no more than 2ml per litre. It also has most effect on the first couple of fills.

On the MOT emissions check what it's failed on , it says Lambda with a result & pass or fail , if it's high CO it's most likely the cat which can sometimes be brought in if it's put on fast idle for a couple of minutes. Depends on how friendly your MOT fellow is.
 

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Not as green as I am cabbage looking.
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Acetone looks vey interesting :D
 

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There is a large thread on WWW.VVOC.com about using acetone, it can also be used in diesel [ owners discretion ] but a lower dosage about 1 to 1.5 ml per litre. Anymore lowers mpg.
 

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you can use chemical metal as a temp fix to test the crack in the manifold and this would throw the emissions. there is something you can get from the hairdressers to go in the tank but i cant remember what it is. personally i'd chem metal the crack first then get a gas test on the exhaust (most places will do it for free or £5).
buy some acertone from the chemist £2 for 500ml and put 2ml per litre of fuel, run a tankfull through normal driving then repeat when empty and take the car to get it gas tested, its worked on a few cars that where close to the emissions pass on mot, and only cost £2 to try
 

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Acetone eh? does it improve performance and economy at all? Wonder what would happen if you used it in larger quantities...
no more than 90ml per tank, it will quiten down your engine, clean all the valves and internal parts (pistons etc) makes the engine run smoother, drops your emissions and supposidly prolongs the life of the engine.

and you can use it in diesels too! it did my astra TD the power of good.

shell optimax has acetone in it but in smaller amounts.

i have used it for over a year now with no problems.
 

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I use Optimax, so would I need to ad any more? and if so, how much?
 
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