You mean the Heat Riser? Nissan calls it the Heat Control Valve.

For a "delete", what most do is twist the flap off the shaft. Or use a cutting torch to get it off.

As long as the shaft is still there, it won't leak.

If the shaft is gone, tap some little plugs in there. You can buy generic plugs at an auto parts store. Or you could hammer some short bolts in there. I'd use a xtreme high-temp epoxy, not JB Weld, but a 2000 degree putty.




OR, go to Pick-n-Pull and get a heatless Exhaust Manifold for $40




Your fuel economy will go down if you run the heatless or "delete". The heatless is designed for work with a water-heated intake manifold/head combo.