Hello

My Vectra has recently started to jump/misfire slightly when changeing gear and accelerating it jumps a couple of times then carrys on fine until i change gear accelerate then it jumps again then carrys on fine it runs nearly as normal aprt from jumpy when accelerating

when accelerateing normally its as above but if i accelerate harder the engine management light comes on and car slows down but after i turn engine off the EMS light turns off and car go back to normal apart from slight jumping desribed as above

Ive took car to two garages to be coded and neither registerd a fault even with engine running and EMS light on

ive had sparkplugs changed and garage has stated it might be a coil pack but i would have thought that would have shown up on EMS with code ? i dont really want to change if not needed

Does anybody have similar experience or can offer any advice ?

thank in advance for any replys

Further to help request above many people suggested replaceing coil pack so i have had it replaced and problem still remains my normal mechanic is stumped so hoping for any further suggestions

thanks