I recenyly purchased a 98 Impreza turbo and subsequently found out it had pistion slap from cold start. Does this cause a problem or should I return it to the dealer I purchsed from.

 

mine does it too, everyone said leave it alone until it is there when warm, take it it doesn't use any oil?

I just let mine warm up and ignore it, maybe mentioning you are not impressed to the dealer as it is quite pricy to fix