Hey I was wanting a catch cab for my Sentra Nismo. Need info.(Former Nissan AA ASE Technician here) It is a myth that a warranty can be voided outright. According to most laws: the dealership has to prove the installed part caused the damaged part in question to fail in order to not cover a repair under warranty.
For example: If you install a catch can (BTW you need two not just one), and then your transmission fails, the dealership cannot say: "HEY! YOU MODIFIED THIS, THAT CAUSED THE TRANNY TO EXPLODE." They have to prove the modification caused the damage. For instance: you install a catch can and the primary cat burns out or clogs, then they find a vacuum leak from the can, then they can say: "your modification created a vacuum leak which caused the engine to run overly lean/rich which killed the catalytic converter."
IF you get a catch can, avoid the ebay and amazon ones. They literally don't do anything. They are empty can that collect nothing. You need a properly baffled and filtered can. Mishimoto sized ones are SUPER tiny and need to be emptied nearly every month which can be annoying. I make catch cans for the Sentra Turbo, Juke, and new Altima just because what I was finding on the market was basically crap. Also: Use proper oil resistant lines. The cheap catch cans come with terrible quality lines. I cannot tell you how many cars I have had brought to my shop with cheap catch cans and drivability issues, only to find that the hose they used split or slipped off after only a few weeks.
Also look into catch can routing. There are two lines on the pcv system on a modern nissan. One goes from the Valve Cover (VC) to the intake MANIFOLD, and one that goes from the VC to the intake pre-throttle. The best way to set up a catch can and reduce crank pressure is to route both VC ports to a single catch can, and then to the intake pre-throttle, then cap off the intake manifold port properly.
Doing this does a few things: Under light load, the crank case is not building any pressure, the pcv valve barely sputters down there, by having the ports go to fresh air in the intake pre-throttle, you keep the crank case at atmospheric pressure, which reduces the amount of oil vapor being pulled into the intake tract through the pcv system. It also means at higher loads and rpms: the vacuum force in the intake pre-throttle is always negative so it is always pulling air from the crankcase. A PCV system that runs to the intake manifold will sometimes see 0 to -1inhg vacuum, which is not enough to pull from the crankcase, which then forces the other port to do the work anyway, and at higher loads and rpms is when you get the highest crankcase pressure so that is when you really want it to vent proper. OEM set their PCV's up for emissions, not performance or reducing oil in the intake system, which is why they do it the way they do.
@rogoman as for why does he need one: Modern DI nissans do not fuel wash the valves, which causes carbon and oil build up to occur very quickly, a catch can prevent the oil vapor from getting to the valves (if properly set up of course). Modern PI nissans put the fuel in a position that prevents fuel from fully washing a valve like in older models, which can cause sections of valves to build up carbon/oil which can mess with power and fuel economy. Every vehicle I purchase, new or old, gets a catch can set-up. A ~$200 investment up front can save a lot of headaches down the road.
The photo has a juke on it, but the sentra is the same thing so: https://thefastreligion.com/collections/intakes-v2/products/fastreligion-hidden-oil-catch-canHey I was wanting a catch cab for my Sentra Nismo. Need info.
Says the link is broken. Can’t show URLThe photo has a juke on it, but the sentra is the same thing so: https://thefastreligion.com/collections/intakes-v2/products/fastreligion-hidden-oil-catch-can