That is not true sir...i have a non recirculating bov after the maf and it runs perfectly fine...only difference is you get a rich A/F mixtures for half a second when you depress the accelerator (shifting gears). As long as your bov is not opened at idle there is no problem at all... Iv had this BoV for 3 years and iv never had a problem with it even though i beat the hell out of it at the track!

 

The higher you go in boost will also effect how rich it gets when you let off. High enough boost values and your car could nearly bog out and/or smoke spark plugs. But yes, you shouldn't have any problems until you go out of boost

 

that's what I would consider running like ****...fowling everything downstream of the fuel injectors....plugs, O2 sensors, your cat if you run one...in Ontario, I have to pass DriveClean every 2 years so I need a cat, and the engine needs to run perfectly....also you're throwing away efficiency, thus power and money, negligible as it may seem, it adds up...