After 2 mn tritons I have eliminated all causes of engine light problems, surging and stalling for $50 and in 1 day.
Cleaned intake manifold using the guide on this forum. This fixed surging.
Added blanking plate and drill 12 mm hole in throttle butterfly.
Cleaned maf and map with contact cleaner.
Most importantly removed and serviced/modified scv. This fixed the stalling and engine light
Car runs like a clock now.
Added secondary fuel filter just for good measure