Inspection After Removal

WARNING: This page is about a different car, the 2012 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

Surface Distortion

Check the flatness of each exhaust manifold flange surface using suitable tools.
Flatness limit: 0.3 mm (0.012 in)
If measurement exceeds the limit, replace the exhaust manifold.

Fig 1: Checking Exhaust Manifold Flange Surface Using Feeler Gauge And Straightedge
Courtesy of NISSAN NORTH AMERICA, INC.