my 98 vectra 1.6ls has a dead spot and engine light comes on?

Hi, can anyone help with this, i have a 98 model 1.6ls
and since comming back from garage after the mot it has a dead spot when driving round town and at speed, and although it hasn't cut out yet , it seems likes it's only a matter of time.
Also engine electronics light comes on but does not stay on, any help greatly appreciated