I have a problem that I cant find any answer to, search the net for hours...
I got myself a 2004 RS mk1 with 144000km on the odometer.
3" Mongoose, IC Pro alloy, special map since 2004, K&N air filter.


Whit cat on I get smoke when I floor it and change gear, when I de-cat it I get a puff every time I change gear, if I floor it I get a huge cloud.
The former owner did an overhaul on the turbo, made no difference at all.
There is no smoke at start-up, could not be valve seals then?
It has a really bad idle when I have the cat on, stops 1 of 3 times when I hit the clutch for a junction.
If I change gear and support with gas, don't let the revs fall down, then no smoke...
It don't seems to use oil or water, new spark plugs fitted (Denso), cleaned the air filter.
There is a little dent on the oil return from the turbo.
Checked the vacuum pipes for leakage or bends.
The smoke looks blue in the mirror but I'm not sure because of black tinted windows (its not white smoke).
Black soot in the end pipe.
It run like a rabbit on speed, so cant say there is any other fault on the engine.


Anyone with ideas about what to do next?

Sorry for my bad English.