[boldnbrave]

I have purchased a 1.4 tfsi golf 58 plate
and it keeps failing the emmisions
at idle all is ok lambda etc
but on the fast idle the lambda drops significantly and the c.o.
sky rockets
ive changed the cat and all the probes and it hasn't helped there are no fault codes to help either

does anyone have any help please as its mot time

many thanks

[strikeforce]

Very little clue without dtc but try cleaning maf sensor and change the fuel pump (weak fuel pump). they both tend to drop the lamda and lean out the fuel-air mixture.

[boldnbrave]

Thank you for your imput sir
will give it a try

[jojo1212]

Change the PCV
try

[wirefan]

Pcv you can test manuelly and vag have revised pcv at store , old versions are ....