Different engine, maybe not applicable . . . but I removed the "emission control pipes" after cleaning out our 2000 TC carbs which were clogged with resin/gritty 'crud' from these pipes, connectors and the carb body. Blanked off all the carb connections. I feel confident this has made achieving a balanced tune between the carbs easier, perhaps by reducing the variables involved. Also, given the history of these fittings, I don't feel I'm adding any significant pollutants to the planet, given the total lifecycle savings of using the car instead of buying new !
I retained the crank case breather, with the exit pipe now sending gasses through a filter and capture globe, and a motorcycle-style venturi exit to draw a vacuum through the filter as we move, so drawing gasses out of the crankcase and avoiding pumping them straight back into the carb/engine. I get around 2 mm2 per 1000km of hard driving, so if this volume changes I'll treat it as a prior warning of problems with my piston rings, etc. I'm sacrificing the negative crank case pressure at idle, but leaks from the the crankcase gaskets aren't a problem at this moment.
My 2c
