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Discussion Starter #1
hello went for its mot today and failed on emissions carbon monoxide idle
2nd same again fast idle excessive.

ive had redex in her and gave it a good bit of revage :hihi
new plugs etc and it still smells odd and smokes white smoke, like if it was cold but does it when rev'd hot..
passed on HC AND LAMBDA
but fails CO.

what do it need to pass? help please:thumbsup:thumbsup

car seams to bog down abit now like its got slower over the last month or two and mpg keeps going up and down.
then the next minute its got full power again its so odd.
 

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Sounds like it could be loose guts in your CAT? Had the same sort of problem on a motorbike years ago, guts come loose and block the exhaust causing it to loose power. Try jacking the car up and tapping the cat with a rubber or nylon mallet and see if u can hear anything rattling around in there
 
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Discussion Starter #5 (Edited)
nope going to be a new one i think.
fast idle co max 0.30% .... mine 0.52%
2nd fast idle max 0.30% .....mine 0.58%
natural idle max 0.50%....... mine 0.82%
 

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hi pal have you had in on a computer? and also as kevin mentioned you need to check the cat to see if its droped internaly. then i would check to see if the vacum/air pipes around the inlet the main 1 is from the air filter box to throtal body have any leaks or cracks. get a can of brake cleaner n spray around the pipes while your engine is running n if you have an air leak you will hear the engine change sound on idle.
 

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Discussion Starter #9
going to try a used 02 and see if it helps before i spend alot of a new 02 and not wanting to buy a new cat as i want to decat it soon, got all the decat waiting to go on.
anyone know of a fuel treatment what helps lower it? ive tryed redex but not any different also put some vpower in her and it did pull abit better but only got 20miles to £10 and still didnt drive aswell as it did on normal fuel months ago.
 

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A lambda sensor on a E36 won't show a fault code if it has lost efficiency. Only suitable diagnostics will show if the sensor is performing how it should be. :thumbsup

So in other words, you can have a sensor playing up, but won't put the fault light on, it will give you higher emissions and there won't be a fault code for it.
 

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Or a cheeky trick, if it's only to high by a little bit, get an old oil filler cap and drill a hole in it, it will drop emissions a tad, just hope the tester don't notice it! Also only put the drilled cap on just before you get to the station otherwise you will have a mess in your engine bay!
 

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Well it got MOT'd at my work lol so I think we might just check that now haha :) Kev mate just give it a good service, fuel additive and chenge that O2 sensor too and its a guarenteed pass!
 

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I had a similar problem with mine at the MOT station, lucky enough he is a friend of my brothers and got the mechanic from next door who went under and straight to a sensor took it out and found out it was full of water. Apparently a very common thing as the drainage pipes that come out via the bulkhead area can drip directly down onto the sensor wire and then into the connector.

He took it out, blew it dry with an airline, sprayed electrical cleaner on it and told me to go drive it for an hour to burn off any fuel in the cat and come back.

I came back and it passed with flying colours. From memory it was the lamnba sensor and he was directly under the engine bay so I assume it was the front one (if there are two on this model?)

Worth a try as it's certainly the most cost effective and easiest solution to look at first.
 
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