xud Berlingo boost

[xudlingo]

Does it smoke at all when your foot is hard down? Could possibly be weak mixture if not.
@ 20 psi, the boost has obviously been 'adjusted', if the pump hasn't been adjusted/adjusted enough, then it'll be weak under full load at higher revs. Easing off decreases the load and boost, it may well have the correct air fuel mixture then.

So does it smoke when up the revs (at least 2500rpm) and foot planted hard down?

Mixture is not best smokes a bit but gets bad if keep foot down on motorway as boost creeps down can some times go as low as 8psi

I do think it's the exhaust as sounds like it has a supercharger coming out the blowing exhaust. I will rip exhaust off and take it a spin with just downpipe see what happens ( with ear plugs)

Thanks