Hello again! -Truck is a 2002 Ranger 2.3 5MT..... I have an exhaust leak where the exhaust manifold connects to the pipe with the catalyst and O2 sensors. The bolts are tightened down to the point that the flange is bottoming out on the studs. It will not go any further and there is still a noisy leak. There is no gasket or donut between these two assemblies- just metal on metal. Am I missing a component here? Is there supposed to be some kind of seal here other than metal on metal? Thanks in advance! -James

 

After doing much research, I discovered that there is a donut that goes there. Napa part # EXH 31372 did the trick for me. It sealed it nicely, now the truck is whisper quiet!
BTW, the gasket that goes downstream, between the catalyst section and the muffler/tailpipe is Napa part # BOS 2561023.

 

Good work. Yes, that donut is important.