2005 Toyota Matrix Owners Manual - Page 487

'05 MATRIX_U (L/O 0409) 4. Remove the filter from the filter outlet. Inspect the filter on the surface. If it is dirty, it should be replaced. When installing the filter in the filter outlet, keep the arrow pointing up. INFORMATION The air filter should be installed properly in position. The use of air conditioning with the air filter removed may cause deteriorated dustproof performance and then affect air conditioning performance. 163 2005 MATRIX from Sep. '04 Prod. (OM12892U)