I have myself an EA Fairmont CPI It lacked all sense of power and guzled petrol like a lambo. Past 2000rpm looses power, under 2000 she crawls i find a spot about 1500 2500 that is my peak.

Had the ecu sent and tested. Fine.

Had the oxygen sensor replaced, now she doesnt burn incredibly rich anymore, and past 2000 she gets more lively.

But still no power before 2000, ridiculously crawls from 0... ideas?