Short term fuel trim Peugeot 206

Hello I have a Peugeot 206 1600 16v and I have a problem during cold start. When I start the engine and the car is cold it runs into open loop mode for 10 seconds and then upstream heated oxygen sensor starts to take readings and car goes into closed loop. During this transaction (open loop to closed loop) engine starts shaking and then fuel trim rises until it becomes -24 and ecu returns into open loop mode, oxygen sensor shows again 0,45v, fuel trim becomes 0 and car stops shaking. Then after 5 minutes (it depends the weather) oxygen sensor starts to take readings again and ecu returns into closed loop without engine shaking. After that car runs fine during idle and short fuel trim is around -2 (only negative). Long fuel trim is constant +3 all the time.. I noticed that short fuel trim jumps from negative short fuel trims to positive and reverse when I try to park the car.   Every part of fuel system has been changed except evap canister ( I tested purge valve and  it's ok). I placed new map, new air filter, second hand electronic throttle body, new upstream oxygen sensor, new coil pack and spark plugs, I tested another ecu but nothing changed.. I think the problem started when I changed exhaust manifold, I placed a high flow one which i took from a peugeot 106 vts. Upstream oxygen sensor's location changed, it placed at the collector without extending its wires. I placed a catalytic converter under the car and the downstream oxygen sensor after it by extending it's wires. I never programmed ecu. Any help?