2002 Vauxhall Zafira pulls to left when steering let go

your trackin in is out on one side thats why it is doing that

if you have tracking done ,,this will solve the problem,,but mi say but check your tyer on the side you may need to change the tyer pall,,,as the tracking will ware it on one side bad ,,,dave

firstly check the tyre pressures as if the tyre pressures are low that would cause the vehicle the pull to one side and if the problem is still there then have the vehicle tracked up and if there is anything else a miss they they will tell you what the problem is and give you time to get it sorted