A6 Emissions failure

[fgsrule]

Hi there, my father has a '94 model A6 Avant 2 litre (ABK engine code).

Only 125000 miles on the clock but has failed on emissions at MOT time. Spark plugs, leads, dist. cap, leads, air filter, ect all god (recent full service).

Heres the MOT tech specs for those of you that understand them.

1st fast idle test
CO 3.11% (limit 0.3%)
Lambda 0.924 (limit 0.97 -1.03)

2nd fast idle test
CO 3.86% (limit 0.3%)
Lambda 0.896 (limit 0.97 - 1.03)

Natural idle test
CO 2.49% (limit 0.5%)

Hydrocarbons slightly up but not enough to fail.

I THINK this looks like an airflow meter fault. (it is original on the Audi - 1994) No air leaks that i can find in servo pipework or manifold gasket.

Performance seems a little 'flat' and lacks power (seems to run out of steam at 85 mph) also the idle is rough from cold start, really spluttery and also jerks and 'kicks' when backing off the throttle or driving gently in traffic, wheter warm or cold

So what do you guys reckon - airflow meter or lambda sensor?

If its air flow will have to get an remanufactured one as Audi want £400!!

Please help - as he has now got my car till its fixed!!

Email responses to fgsrule@yahoo.com much appreciated. Thanks

[DieselTrader]

Hi, I would first of all get a good quailty injector cleaner, add it to 1/2 tank off fuel and give the car a good blast, this may unblock any injectors which may be the cause of the emmisions failure
regards DieselTrader.co.uk