hi there, disconnect the neg lead off the battery & remove the 2 connectors off the ECU again, you may have bent a pin or more. If you see any bent pins straighten them. If all pins are ok, re-fit the conenctions & leave battery off for 30 mins. Then start the car again. If the problem persists most likely the ECU is damaged.
I had a 2003 1.6 TS that would start, only rev to 1200rpm when cold & 800 when hot, its cooling fan was awlays running & it had an errors stored referencing Throttle position, temp & cam sensors. It turned out the ECU wasn't outputting 12 volts on ONE pin common to 3 different sensors [ cam, temp & throttle ]. I got an replacement ECU form Alfatuner. 3 week later a good friend of mine, his wife car ahd driven to work ok, she started that evening to come home & the engine woudl not rev above 1200rpm, with the fan always runing. He rang he, I advised him & he too ahd to replace the ECU