vectra engine light intermittent

[anthony25]

have a 2000 vectra b and sometimes the engine light comes on the dash when i start the engine and when it does come on the car drives like **** very sliggish etc,but i can switch the engine off start it again and the light goes car drives great,but ive noticed that when i turn the key if it takes a couple of seconds for the engine to turn over thats when im getting the light on if i turn the key and the car turns over straight away the light doesnt come on any ideas??..posted this earlier didnt get much response thought id throw it out there again

[chas2008]

when the light comes on and it runs rough thats because the electronics are detecting a fault somewhere and the ECU is doing just enough to get the engine to run, its called 'get you home mode' or 'limp mode'.
The chances are whatever fault its detecting is probably one of the sensors but it will be difficult to pin down without a diagnostic kit i.e. tech 2, Vauxhalls are well renowned for the MAF sensor (mass air flow) breaking down.

[gary2411]

could be the cam sensor throwing a fit