emissions test

[dobbin]

some advice needed . car failed mot today on emissions said should be 0.30 but mine was 370 . so then i told him no cats were fitted but he said still to high even without cats . anyone know what would cause car to run like this . all new sensors and maf and lamda probe. exhaust at back of car is black and sooted up , no error codes on vag com . luckly i know mot man and car will pass mot tonight. but what would cause car to run that high or is this figure ok without cats and homefries

[S2central.net]

homefried ecus do NOT mess around with MOT emissions... it runs closed loop with lambda probe doing its thing at normal or fast idle. Plenty folk on same software as you without such woes.

Are you sure the correct MAF & lambda probe were fitted - and the correct (RS2) fuel injectors ?

Only other obvious contributor to such a highly rich looking mixture would be if fuel pressure is stupid high - worth checking that, but ECU should throw up a fault if it cannot adapt for some deviations.

Post up 10 blocks from measuring block 000 on a warm idle - that might shed some light.

[dobbin]

cheers paul will check vag com again tonight. gen lamda probe and maf fitted by myself but injectors look std and original was wondering about faulty injector.

[dobbin]

just took out all new spark plugs all sooted up black. so thought i would check fpr ,
cannot get fpr to open on mitty vac , would this cause my problem

[S2central.net]

You really need a fuel pressure gauge fitted to see WTF is happening. On RS2 you should nominally have 3.8bar pressure ABOVE manifold pressure - that translates to ~3.3bar on idle.

If for example the control hose to FPR is split or disconnected then it would 'see' ambient pressure... which would make it run rich under vacuum/idle/cruise but lean and horrible under boost.

If its always rich then maybe the FPR internals are messed up... see if you can find a friend for an FPR swap meet - easy enough changed over if you dont mind a little spilt fuel.