No power when cold. Blobeye STI

So when my engine is cold, ie just started and has been running for 60 seconds, I can hardly pull away on a very slight incline without the engine stalling.

After a few minutes I'm actually able to drive and I try and keep below 3-3.5k until the oil has warmed up, however I still notice a huge lack of power at this low rpm.

I've asked a few local people who have the same car, none of them have this problem. I've done some research online and didn't come up with much either.

However I did come across one interesting thing, apparently if you have forged pistons then they expand a lot more than stock ones once warm. This means that when they're cold they won't fit correctly which will cause piston slap and no power until warmed up.

Does my no power issue seem like forged pistons? Or maybe the ECU was changed to reduce power when cold?