Hello and help; seicento ecu map problem

Hi, straight to the point, timing blet went 2 months ago, sorted that, 2 weeks later the car started to lose power and then died, recently I have serviced the car, oil, plugs etc. new rear exhaust box fit,then changed MPI and OHC sensor, fault tester comes up with p0105 and p0120, when i turn over the engine it fires for a sec and then dies, after that it will not fire just turns over, So any thoughts; I was thinking ECU or map sensor, if it's either of these can anyone tell me where the ECU lives (found the PS ecu) but i belive theres a second one somewhere. Help please thanks in advance Mike