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CazzaVR

Failed MOT today...

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Got a CO2 reading of 0.33- gutted as it only needs to be 0.3. The testers tried a few times but it wouldn't go any lower :( Passed on everything else :)

 

They reckon because it's so close, it will almost certainly pass if I let the petrol go right down and add some Wynn's injector/fuel treatment. They also suggested cleaning the air filter. Gonna try both of these.

 

Any other ideas? Car's in for re-test on Tuesday.

 

Cheers!

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best thing is fuel line and injector cleaner , put another bottle in when you go for the re test and like you have said change your air filter as well and all should be good , may sound stupid but what condition is your engine oil in as i have known very poor quality oil , dirty oil can also effect your c/o levels on a mot :)

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as said above oil can get contamiated with petrol passing the rings and as it warms and turns to petrol vapor the crank case breather feeds this vapor back into the inlet manifold to be reburnt this can lead to a richer mixture,as its so close try a hard 30 min drive before the test to burn off all the petrol vapor sometimes getting the engine hot can sort out small over readings of co2

 

 

rob

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Whatever the mixture going into the combustion process is, the lambda sensor will alter the fuelling to achieve lambda one if it is within its trim window. You need to get a fault code scan and a pre cat sniffer port gas reading to see what the pre cat mixture is. If it is around lambda one and you have no fault codes, you have an inefficient cat which usually responds to a good thrashing prior to the test. If it doesn’t respond, you need a new cat which isn't uncommon on the 9A as they use a little more oil than is healthy for cat longevity.

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Cheers guys! Giving it a good thrash sounds right, as it did come down after a couple of goes.

 

Had a service a couple of months back with castrol magnatec oil, so that should be fine.

 

When I removed the panel filter, it had a slight wiff of petrol.

 

It passed on all the other readings, it was just the exhaust CO2 it failed on.

 

So, injector cleaner and a good thrashing! I'll also give the air filter a clean as it's now out of the car.

 

Thanks :)

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Right, it's failed 2 retests with similar readings.

 

Took it to my local specialist, who got a similar reading (0.36 CO). However, he's told me that the MOT place should've consulted their book as soon as it failed, because they have an older test machine. The book CO pass value for the 2.0 16v is 0.5! Anyone know if this is correct?

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i will aslo check but as pete TDI has said what year is it ?

WOW ive just spotted your also a life long HAMMERS fan , why say it so quietly im proud of it living in a house full of gunners then beleave me ive heard every insult there is LOL :multi:

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lottysvdub, nice one- COME ON YOU IRONS! Let's give the Spuds a good old beating this weekend!

 

peteTDI, K reg 1993.

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Right, have found out that the idle test value is 0.5% CO, and the fast idle is 0.3% CO.

 

Failed it's retest AGAIN today, with similar readings between 0.33-0.39% CO on the fast idle. The regular idle, and everything else passed easily.

 

I'm fast losing patience with this, and the garages. I'm absolutely skint and can't afford anymore work on the car.

 

I reckon it must be the mixture that needs a slight adjustment, and I've found instructions how to do this (in Jim's idle thread) and it doesn't look too difficult. However, I'm crap with electrical stuff (multimeters etc) and don't have a clue how to use it. Is there anyone in the Glos/Bristol area who knows their stuff who could give me a hand with this please? Beer tokens available :wink:

 

Cheers

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Hi mate,

 

Yeh, it sucks :( My local specialist is looking at it again tomorrow- he thinks it may be a temp sensor or something. He's a bit stumped, but reckons it's running slightly rich. Think he could be right, as MPG isn't as good as it should be. I'll also suggest testing the pre cat CO. He doesn't want to fiddle with the mixture via the metering head, as he says it's too fragile.

 

Last time he checked the ECU for faults and there weren't any.

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Car still at the garage. Still not sorted- gonna try a new Lambda today. They think it may be the FPR if the lambda doesn't sort it. They think it's prob not the cat as it's only 2 years old.

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Yeh, got a K&N panel filter. I actually took it out on the last retest and it made no difference :(

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man its only .3 out why wont they just let it pass , i hate faggot garages :)

 

yeah it might work paper holds back the flow more than an k&n

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