Lambda failure

[Sam Russell]

My car faile on emissions because of Lambda value. Car Passat 2000 1.8L petrol APT engine non turbo.

Allowed Lambda range 0.97 - 1.03 Actual value measured 1.10 Fail.:zx11:

Last time it was 1.00

What is the likely cause? CO = 0.00%, HC = 4ppm (both well within limits).

The car runs well and sometime is not easy to start, but does eventually after a few cranks. Tickover is 800rpm, 1100 from cold. No unusual wheeze or coughs.

It does need a service, air filter, oil change, etc. Only got 56000 miles on, and only driven 6000 miles in the last 18 months.

Any help appreciated.

[Crasher]

You need a fault code read, guessing usually results in a waste of time and money.

[Sam Russell]

You need a fault code read, guessing usually results in a waster of time and money.

Well, got a garage to check, but they could not spot any obvious fault. Live data led them to blame anything and everything. They are going to check again, tuesday.

Could it be as simple as spark plug, or air filter blocked?

[VAG-tech]

Actual value measured 1.10 Fail

What is the likely cause? CO = 0.00%, HC = 4ppm (both well within limits).

Lambda 1.10 suggests an excess of air in the exhaust gases, it could be as simple as a pin hole in the exhaust system.

[Sam Russell]

Thanks for that, I will check out for any leaks.

[Sam Russell]

Well, I have had a garage look at it and he fixed a few small things but cannot get the engine to go into closed loop control. At 2200 rpm it is perfect, but at idle it is off the scale rich. Given I had a wire fault before, it could be that again, si it is back to the multimeter and prodding away to find it.

He said it is not the lambda sensor itself, but it is related to it.

Any ideas?

[Crasher]

I would try a new Air Mass Meter.