I have a cold running problem with an MY98 uk turbo,when starting from cold,the engine will rev to about 4K,but anything after that it hesitates,and the engine check light will flash on breifly,it has a power fc ecu fitted,and i have changed the coolant temp sensor,allbeit a second hand item,once the engine has warmed up,the problem dissaperes,anyone have any ideas,could it be the maf ?

 

bttt