Aaarrrgghhh!!! Misfire

[nathanwedge]

Bloody hell it's back again!! Starting to think the lamda sensor is faulty they surely can't be that sensitive?

[AdrianC]

they surely can't be that sensitive?

They can and are. It's kinda the whole point of 'em.

If there's too much oxygen in the exhaust, the lambda tells the ECU that, and the ECU puts more fuel in.
If there's too little oxygen in the exhaust, the lambda tells the ECU that, and the ECU puts less fuel in.
It's all because catalytic converters are fickle things, and need exactly the right amount of oxygen if they're going to work.

For the lambda to measure exactly how much oxygen there is, the exhaust has to be utterly gas tight before that point. ANY exhaust leak is going to throw it out. A dead lambda is better than a live one giving a false reading, because the ECU will just decide it's dead and ignore it.

[Ian Hulley]

Never assume a new part is a good part .... especially if you buy them from certain suppliers

Ian

[nathanwedge]

Turns out vw's only work with Bosch sensors, spent ages cutting the old one out and managed to get it fitted, works like a dream now I'm ordering a spare one as they're obsolete now spoke to a guy at www.lambdapower.co.uk really helpful and nice bloke. The moral of the story is don't fit pattern junk on your pride and joy

[California Dreamin]

Yes definitely... one component where 'cheap OEM replacements are likely to give more trouble than they are worth. However, you don't necessarily have to go Genuine (as in from VW) on these but there are only three manufacturers I would trust:

NGK (NTK)
http://ngkntk.co.uk/index.php/technical ... a-sensors/

Bosch
http://www.boschautoparts.com/oxygensen ... nsors.aspx

Beru
http://www.beru.com/taxonomy/term/41/all

Mines had an NGK (NTK) in it for 3 years now.


Martin