2012 Honda Civic EX 4-door Sedan Oil Catch Can
i4 1.8L Engine, R18Z1
First of all, below are some elementary-grade diagrams =D that will try to explain why an oil catch can may be needed for your car.
DIAGRAM 1:
Air comes into the engine via the air intake, goes thru the air filter and then to the engine, after combustion the air is dirty (SMOG) and it goes thru the catalytic converter to clean itself a little bit and then it goes out the exhaust.
DIAGRAM 2:
The PCV valve releases accumulated air pressure (SMOG) inside the engine as to not blow the engine. If this SMOG is just released out of the engine, then a lot of contamination would end up in the Earth's atmosphere.
DIAGRAM 3:
In order to not release SMOG without the SMOG going thru the catalytic converter, a hose is connected between the PCV valve and the air intake in order to re-route the SMOG into the engine again so that it eventually escapes thru the catalytic converter to clean itself a little bit.
DIAGRAM 4:
So the PCV system is there to not over-pressurize the engine AND to not release un-cleaned SMOG to the atmosphere. Unfortunately, the PCV system for some cars tends to introduce engine oil into the combustion chamber, it's supposed to only introduce SMOG into the combustion chamber. When engine oil is introduced to the combustion chamber, such oil will tend to make your cylinder head, combustion chamber, intake/exhaust valves get carbon build-up. This is where the oil catch can comes into play. The oil catch can will try to do just that, catch the oil before it gets into the combustion chamber. You install the oil catch can anywhere between the PCV valve and the air intake.
My personal opinion: most cars don't need an oil catch can (specially non-turbo, non-SI cars), cars can generally tolerate carbon build-up, by the time you have excessive carbon build-up you'll probably have more than 200,000 miles in you car and you'll be getting close to buying a new car anyway. This is exactly why I bought a cheap $20 oil catch can from the flea market (commonly known as Ebay), it this cheap catch can catches any oil then good, if not then who cares =D
Installation took about 30 minutes because I could not find a better location for the oil catch can. Now that you have these pictures it should take you 15 minutes.
i4 1.8L Engine, R18Z1
First of all, below are some elementary-grade diagrams =D that will try to explain why an oil catch can may be needed for your car.
DIAGRAM 1:
Air comes into the engine via the air intake, goes thru the air filter and then to the engine, after combustion the air is dirty (SMOG) and it goes thru the catalytic converter to clean itself a little bit and then it goes out the exhaust.
DIAGRAM 2:
The PCV valve releases accumulated air pressure (SMOG) inside the engine as to not blow the engine. If this SMOG is just released out of the engine, then a lot of contamination would end up in the Earth's atmosphere.
DIAGRAM 3:
In order to not release SMOG without the SMOG going thru the catalytic converter, a hose is connected between the PCV valve and the air intake in order to re-route the SMOG into the engine again so that it eventually escapes thru the catalytic converter to clean itself a little bit.
DIAGRAM 4:
So the PCV system is there to not over-pressurize the engine AND to not release un-cleaned SMOG to the atmosphere. Unfortunately, the PCV system for some cars tends to introduce engine oil into the combustion chamber, it's supposed to only introduce SMOG into the combustion chamber. When engine oil is introduced to the combustion chamber, such oil will tend to make your cylinder head, combustion chamber, intake/exhaust valves get carbon build-up. This is where the oil catch can comes into play. The oil catch can will try to do just that, catch the oil before it gets into the combustion chamber. You install the oil catch can anywhere between the PCV valve and the air intake.
My personal opinion: most cars don't need an oil catch can (specially non-turbo, non-SI cars), cars can generally tolerate carbon build-up, by the time you have excessive carbon build-up you'll probably have more than 200,000 miles in you car and you'll be getting close to buying a new car anyway. This is exactly why I bought a cheap $20 oil catch can from the flea market (commonly known as Ebay), it this cheap catch can catches any oil then good, if not then who cares =D
Installation took about 30 minutes because I could not find a better location for the oil catch can. Now that you have these pictures it should take you 15 minutes.
I always thought my pollution lever was really cool.
I don't think a oil catch can is really needed in a non boosted car. Just run some fuel injector cleaner my favorite is Lucus fuel cleaner in the one gal size $27 to keep combustion chamber clean in the gas tank, clean your pvc with a cleaner. 
boosted cars seem to throw oil a lot more and it will sit in the intercooler.
But on other had a catch can is quite cool looking. I ignore people too butt not really. Actually you could just run a small tube with a steel filter downward and just vent it to the ground like they did in the old days, you wouldn't have to drain the tiny bit of oil then. I didn't see a lever to drain the oil out-could be water in it too. I have to look into this problem some more, however tiny it is. I see some people actually run two catch cans. Quite interesting actually, may have to put it on my list of things too do as the honda engine spins very fast-so far it looks like it isn't needed on a non turbo.
Oh add one oil spill.
Try and help when ever I can. I had forgotten I took a picture of them at first.