So car is a jdm 2003 sti, milltek decatted full system, fmic kn cone fikter,walboro pump, pierberg 3 pprt. Remapped.

now all of a sudden last weekend, wouldnt boost.

cleaned bcs, no change, left off vac line to bypass bcs, boosted to 1.4 where i let off.

sourced new identicle bcs and fitted.

Now it boosts to 1.4bar (mapped for that) if i start WOT from 4k+, but if i load the engine and try boost from 2k it stutters and pulls revs at 4k and continues to overboost to 1.5 and doesnt feel right atall..

any ideas? Is it actuator/ sticky wastegate related ?