Misfire

[able]

My VW Polo (2000, 6N2, AUD) has started to misfire (Only error on VCDS shows on 2,3,4 cylinders) Gave the engine an oil change, oil filter and air filter. Changed the plugs and leads. But still has the misfire (2700-4000 rpm) from cold it is ok and till around 8 minutes later when it will misfire (when warm/hot) so, changed the O2 sensor and ignition coil module and now a new ECU, but still a misfire, changed over all vacuum hoses,did a compression test (all good 160-163 psi) but still the same consistent misfire at same rpm range. Decided to change the MAP sensor, but strangely with the MAP sensor disconnected it runs fine? So, new MAP installed , but back to the misfire? But with a disconnected MAP sensor it runs fine (cold/warm/hot) What could it be?

Cheers
Able