Emissions MOT Fail

**tracy clarke** · 01-12-2013,11:47 PM

Hi please can anyone give me some advice.
My Car failed its MOT on Emissions Audi A4 1.8 petrol 2000 W reg.
Mot reads
Exhaust emissions carbon monoxide content at idle excessive (7.3.D.5)
Exhaust emissions carbon monoxide content after 2nd fast idle excessive (7.3.D.4)
Exhaust emissions lambda reading after 2nd fast idle outside specified limits (7.3.D.4)

I have been advised by one garage that i need a new Cat converter, but he did say he can not guarantee the car will pass the mot after this has been done and basically told me i would be better off buying a cheap run around for £500!!! I dont want a cheap runaround i want my Audi back.
I have done a little bit of limited research and wondering if anyone can advise me as to the best course of action. Do I start with the Exhaust, advisory says exhaust starting to show signs of deterioration, One site i looked on said this could possibly cause the lambda reading to be out if there are any tiny holes, or do i get new lambda sensors first or go for a new Cat converter first or a cat converter and lambda or all 3???
I am on a very limited budget at the moment and i just dont know what to do for the best!!!!

I do have the results of the emissions test if needed. Just seemed like a lot of typing if not necessary.

Please note i am female and of the worst kind, i put petrol in my car and drive it, i pop it in the garage every few months for oil water tires etc I need everything explaining to me in the simplest of terms

**zollaf** · 01-12-2013,11:52 PM

welcome. to be able to help i would need to know the actual readings from the fail form. just knowing it failed is of no use really, but knowing how far out it is will be.

**tracy clarke** · 02-12-2013,12:01 AM

Ok i think i am reading this correctly.
fast idle Actual limits
co 0.581% <= 0.300%
hc 157ppm <= 200ppm
lambda 1.031 <= 0.970 -1.030

2nd
co 0.549% <= 0.300%
hc 131ppm <= 200ppm
lambda 1.032 <=0.970-1.030

natural idle test
co 0.632% <=0.500%

Hope this is correct

**zollaf** · 02-12-2013,08:49 AM

thats what we need. was the car properly hot when he did the test. that looks like it was tested not properly hot. so did you drop it off and collect it later or turn up and he tested it. if that was me, my tester would tell me to go and thrash the nuts off it for 10 mins and come back.
or, there is a small leak somewhere in the exhaust ?
and does the temp gauge read 90 ?

**tracy clarke** · 02-12-2013,10:18 AM

I honestly dont know. I drop my car off at one garage and they then take it round the corner to the testing station. All i can tell you at this stage is that my car had been parked up for a few weeks as i had not been well. I drove it to the garage about 2 1/2 miles through town. the mot was done and i was given the bad news, I then asked for a cleaning agent to be put through the car the car was then taken for a 15 mile run along the bypass and back and down the country lanes and it still failed. I again am unsure about the temp gauge. As the car had no mot i cant take it for a drive to check unless i can check this by just revving the engine for a while just sat outside. (sorry i did warn you i am a useless female :-p )

**zollaf** · 02-12-2013,10:22 AM

with the engine ticking over, use a rag or similiar to place over and block the end of the exhaust pipe. its best done with 2 people , one to block and the other to listen and try to pinpoint a leak of gas which you will hear as a psssst noise, if there is one.
it does sound like they have tried to get it through, but with the results that close to a pass its not going to be anything spectacularly wrong.
another thing to do is look on the vcds map and find a memebr close by with a diagnostic computer to read any fault codes and check live date for the actual engine temp. if the engine isn't properly warm then it will run rich and fail emissions.