Black smoke

[topher]

lambda (sp) sensor ?

[Sugar79]

erm what that? lol

[audiquattro]

but the temp on my dash stays at 90 when it warms up? and looking at the prevous history of the car from the last owner it had a temp gauge sender unit back in july 2003, would it really need replacing again??

There is usually a separate coolant temp sensor for the ECU.
Could also be a faulty lambda probe.
Topher should be able to tell you more, as he owns a mk4 ?

[audiquattro]

The lambda probe sits in the exhaust manifold or front of the cat, it reads the oxygen content in the exhaust gases, and sends a voltage signal back to the ECU. This allows the ECU to re-adjust the fuel/air mixture to suit.

[Sugar79]

gosh all these god damn sensors are doing my head in lol 
are they expensive?

[audiquattro]

Coolant temp sender should be expensive, not sure about the lambda probe, could be costly 

[Sugar79]

god damn  seems like all my sensors are going down