yes they most often WILL make you test positive.
since little or no research has been done on these compounds and their pharmacokinetics it really impossible to give any baseline of how long between consumption and a clean test.
btw- most of them are either steroids or are converted into them. PH is a loosely used term. but keep in mind that "steroid" does not mean "effective", it just means that it has the right structure- though it typically does denote some activity.
obviously the methyl compounds are more bioavailable and effective (at least they do have activity), but also a lot less safe and even "more" unknown than most other PH.