Canadian cars don't have them. Only us tree huggers to the south.
Depends of year and location. SAI is used to heat up the catalytic converter and the wideband quicker, this way the car will go on closed loop quickly and the catalytic converter will be more efficient. CBUA engine all have the SAI
Hold on now, just to be clear the catch can attaches to the breather hose then either to atmosphere or the intake?
I think I just misread your post haha
Since I'm venting to atmosphere, both my breather and PCV hose vent to the catch can. The catch can itself is at atmospheric pressure (14.7psi) anything over 14.7psi in the PCV system will vent to the catch can. In my case the breather hose that goes to the engine doesn't really supply air as the OEM PCV system
I know the PCV system can be confusing and I feel I should give some explanations, you might already know what I'm about to say, but maybe it will enlight you
When piston ring wear, with cylinder pressure some blow-by gases will go through the pistons ring right into the crankcase. When there is a lot of blow-by gases in the crankcase, the gases have no where to go and it will start building up pressure, which is not good. The solution manufacturers use is the PCV system. With our engine, we have a PCV diaphragm that close under high vacuum and is fully open when the intake manifold reach atmospheric pressure
When the engine is idling, there is almost no blow-by so no need for ventilation. Under acceleration (load), the intake manifold is at atmospheric pressure since the throttle is fully open, there is more cylinder pressure, so more blow-by and the need for ventilation, this is why the PCV diaphragm is fully open when the intake manifold reach atmospheric pressure to let the pressure evacuate in the intake manifold (if you want to get explanations about the PCV diaphragm, feel free to ask)
Then there is a breather than brings atmospheric pressure from the intake piping into the crankcase, it brings fresh air but also make sure that the crankcase isn't under vacuum
The PCV system of our engine is good for NA application but with forced induction, if you vent into the intake manifold, you will be putting boost into your catch can, the PCV system, you will wear the PCV diaphragm faster too. If you want to vent to the engine, you will have to vent into the intake piping before the turbo inlet. In that case, you are running venting to the engine but at atmospheric pressure, yeah the turbo do some suction and will be a little bit more efficient that a setup that vent to atmosphere using the same hose diameter, but a catch can isn't 100% efficient and some blow-by will go through your turbo and then right into the engine
That's why I'm venting to atmosphere because it's cleaner for the engine. With that kind of setup, the diameter size is more important than a setup that use a little vacuum to help with ventilation. The higher the pressure differential is, the bigger the flow / velocity / ventilation is. Since venting to atmosphere will have less pressure differential than a setup that use a little vacuum, it's important to use big hose. When the crankcase will build up pressure and vent to the catch can, due to the bigger volume of the hose (big diameter hose), it will cause a pressure drop, since the blow-by have to fill a bigger volume. Same thing with big intercooler piping, it takes more time to reach a certain boost level because you have to flow more air to fill and reach the same pressure. In our case, the blow-by fill a bigger volume, so the pressure drop and you now have an efficient ventilation
So a setup that vent to atmosphere with big hose diameter is as much efficient than a setup that vent to the engine and use a little vacuum. Having too much vacuum, will suck up more oil vapor and blow-by
If you plan to vent to atmosphere use a good catch can that have a breather filter on top, 2 ports and a good filter inside (oil - air separator) but not to restrictive to allows a good ventilation and to prevent having oil in the breather filter. Honestly, my engine bay stay clean and the filter doesn't get that much oily. Having two port allows more ventilation, if my PCV hose (the one on the valve cover) pressurize due to high crankcase pressure, it will vent through the breather hose (the one on the engine)
I hope this infos helps you, sorry if I'm unclear, English isn't my main language, I'm doing my best