Sluggish 05 Corsa Life 1.0?

Have you even bothered to open the car handbook??
If the engine management light is on it means the cars electronics have detected a faulty or out of range sensor or actuator, and that a fault code has been stored.
The car will also be put into "limp home" mode, whereby the engine power is reduced and the revs are limited by altering the fueling and ignition strategy.
This is to stop cretins carrying on driving faulty vehicles and causing further damage.
Take the car to a garage, they will plug it into their diagnostic equipment and read the fault code(s).

flook
September 2009