Or. Rev. Stat. § 815.195
This section establishes requirements for ORS 815.200. Except as specifically provided by an exemption under ORS 815.205, a vehicle is in violation of ORS 815.200 if the vehicle is required to comply with one of the following standards for visible emissions and the vehicle produces visible emissions that exceed those allowable under the described standard, as follows:
(2) A vehicle exceeds Visible Emission Standard II if the vehicle is operated at an elevation described under this subsection and the vehicle produces a visible emission in excess of that allowed under this subsection. Visible emissions limited under this subsection include any gases or particulates, other than uncombined water, which separately or in combination are visible upon release to the outdoor atmosphere. The limitations on visible emission under this subsection are limits on the percent of transmitted light that is obscured by the visible emission. A vehicle violates the standards under this subsection if the vehicle does any of the following:
[1983 c.338 §486; 1985 c.16 §253]