My biannual SMOG test is coming this summer again, and I want cleaner numbers than last time, which were the cleanest the car had seen in many years because I had acid-washed the failed original 1998 Honda catalytic converter.
Installed an oil catchcan to keep as much blowby as possible out of the intake manifold. It's just better for the engine, too. Original 1998 piston rings with 274,875 miles on them.
But I learned enough about the PCV system to know that I wanted to inspect, clean, and replace my PCV Valve while I was connecting the catchcan to it.
The PCV Valve was dirty! It had a faint slight rattle. After cleaning it inside and out, the rattle was louder and it passed the blowing test of the check valve operation. I even ordered an new valve from Honda for $34 to compare. Amazingly, the new valve was defective (failed the check valve test). So I got my money back and installed my cleaned original part.
And here is the Mishimoto clone oil catchcan (really good quality materials... it's the same can without the name brand). $20 for the can got me all the great features, like the brass screen. Another $20 got me brass fittings and a brass drain valve. Here it is in place. (Still got to add the hose clamps.)
Test driving was awesome fun. Who knows how much trouble the gummed PCV was causing: starting, stumbling and surging, oil contamination, lacquer in the oil pathways, carbon in the combustion chambers, and sludge in the intake runners. It might even have been part of the trouble with the CAT. Most important little part I had no real understanding of before this project.