The answer to your question is that, of course, you are free to do as you like, and not file any Oregon tax return if you don't want to. But that wouldn't be legal; and the Oregon Department of Revenue is known to be pretty strict when it comes to residency issues, and for taxing Oregon taxpayers who attempt to leave Oregon's taxing jurisdiction -- but don't really leave Oregon.
It seems fairly clear (and it would be to an Oregon state income tax auditor) that you haven't completely "abandoned" your Oregon legal "domicile" in favor of a complete move to Washington state . . . because you still have an Oregon drivers license, vehicle registration, voter registration, etc., and you use your parent's address to receive at least some official mail.
Yes, it's true that you may indeed be physically living and working in Washington state on a full-time basis; but the tax laws would still consider you an Oregon resident living "temporarily" in Washington (where temporary can mean anywhere from several months to an indefinite period of years). The correct Oregon tax form that you really should be filing is Form 40 (full-year Oregon resident), and not Oregon Form 40N (nonresident).
You can read more on Oregon residency (domicile) rules yourself, as they apply to state income taxation, on Pages 14 through 16 of the (2016) Oregon Publication 17. A courtesy link to that document is provided for you here:
https://www.oregon.gov/DOR/forms/FormsPubs/publication-or-17_101-431_2016.pdf
In the future, if you truly wish to rid yourself of the burden of Oregon income taxation, you would be well-advised to take all of the necessary steps of transferring your legal documentation, licenses, registrations, bank accounts, etc. over to Washington state, in addition to physically living there on a full-time basis.
In conclusion, we are sorry if this answer is informing you of something other than what you may have hoped to hear. But at least now you know the facts, as far as taxation by the state of Oregon is concerned.
Thank you for asking this important question.
