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This is from the "Another Catch Can" HOW-TO. I am posting this a separate HOW-TO so people don't have to go through 8 pages of information to find this stuff.
Below is a result of some research I've done on my own, and through discussions with other members on the best way to route your catch can and lines, specifically on the breather side.
There are two separate configurations; one for the stock airbox and one for a short ram or cold air intake.
Below are pictures and hopefully a good description of what I've come up with.
Photoshop Skills...
I hope this helps everyone understand what I was going for. As a note, I do not run with the airbox lid off. I took it off for pictures.
MAIN DIAGRAM
The top configuration is with the stock airbox.
This has one line that goes:
PCV ---> Catch Can ---> Check Valve ---> Throttle Body (intake manifold)
The second line goes:
Driver's Side Valve Cover ---> Catch Can ---> Nipple on stock airbox
The catch can on the second line is optional.
This should be the best configuration for the stock airbox, and should retain all factory functionality. Notice there is no breather air filter, as the stock foam make-up filter is in the airbox.
The other configuration is with a Cold Air Intake (CAI). This has a few small differences.
The first line is the same as the stock airbox configuration:
PCV ---> Catch Can ---> Check Valve ---> Throttle Body (intake manifold)
The second line is a little different. It goes:
Driver's Side Valve Cover ---> Catch Can ---> Nipple on Intake
Concerns people have about running the breather line into the CAI:
1. You will pull hot, oily crankcase air into the intake track. A catch can will help with the oil accumulation (which can lower the octane rating of your gas and cause the PCM to pull timing), but it cannot do anything about any extra heat that may be picked up from the valve cover.
2. You will be putting the breather side of the crankcase filter under vacuum. In the factory configuration, the breather line is allowed to pull in fresh air. Remember that even though it is in the stock airbox, it is separate from the air filter. When you hook this line up to the CAI nipple, air moving past the nipple creates vacuum and does not allow fresh air to enter the valve cover; it instead pulls hot/oily air out.
DCX Responds to these concerns with the following: - Thanks Breakin Newz
Straight from Darrel Cox..
"Its best to run the PCV thru a check valve to insure it from leaking while under boost.
Next the engine really benefits from the added vacuum under boost if the drivers side of the valve cover is connected back to the air intake. There is alot of vacuum there while under boost.
To insure no oil gets consumed from the air intake you install a recovery tank between the two.
This way when the car is at idle and under no boost the PCV, hence the name (Positive Crankcase Ventilation) keeps vacuum applied to the engine. When the engine is under boost the air intake pulls a vacuum on the crankcase. Bottom line vacuum all of the time. The rings conform to the cylinders better with vacuum. Also ring flutter is minimal with vacuum keeping oil from being pushed by the rings and up onto the top of the pistons and combustion chambers. Out of all of the engines we have disassembled over the years you see it every time (the ones that are not connected to the air intake) also remember that engine oil added into the combustion process greatly reduces the fuels octane. This can causes unwanted detonation and spark knock. The crank seals, valve seals, and cam seals are designed around this vacuum. Also this greatly reduces windage in the crank case further adding proper oil control and some added performance."
ACTUAL PHOTOS W/STOCK AIRBOX
Overall Engine Shot
PCV Side with $20 Catch Can installed
PTP Check Valve and Breather-Side $20 Catch Can
Breather-side routing, top shot; Make-up filter
Breather-side Catch Can, side shot - this is where you can see the breather line running into the stock location (make-up filter)
Make-up Filter inside the airbox
In about a week I will borrow a short ram and get pictures of the proper routing with an aftermarket intake.
Feel free to post questions or comments!
Below is a result of some research I've done on my own, and through discussions with other members on the best way to route your catch can and lines, specifically on the breather side.
There are two separate configurations; one for the stock airbox and one for a short ram or cold air intake.
Below are pictures and hopefully a good description of what I've come up with.
Photoshop Skills...
I hope this helps everyone understand what I was going for. As a note, I do not run with the airbox lid off. I took it off for pictures.
MAIN DIAGRAM

The top configuration is with the stock airbox.
This has one line that goes:
PCV ---> Catch Can ---> Check Valve ---> Throttle Body (intake manifold)
The second line goes:
Driver's Side Valve Cover ---> Catch Can ---> Nipple on stock airbox
The catch can on the second line is optional.
This should be the best configuration for the stock airbox, and should retain all factory functionality. Notice there is no breather air filter, as the stock foam make-up filter is in the airbox.
The other configuration is with a Cold Air Intake (CAI). This has a few small differences.
The first line is the same as the stock airbox configuration:
PCV ---> Catch Can ---> Check Valve ---> Throttle Body (intake manifold)
The second line is a little different. It goes:
Driver's Side Valve Cover ---> Catch Can ---> Nipple on Intake
Concerns people have about running the breather line into the CAI:
1. You will pull hot, oily crankcase air into the intake track. A catch can will help with the oil accumulation (which can lower the octane rating of your gas and cause the PCM to pull timing), but it cannot do anything about any extra heat that may be picked up from the valve cover.
2. You will be putting the breather side of the crankcase filter under vacuum. In the factory configuration, the breather line is allowed to pull in fresh air. Remember that even though it is in the stock airbox, it is separate from the air filter. When you hook this line up to the CAI nipple, air moving past the nipple creates vacuum and does not allow fresh air to enter the valve cover; it instead pulls hot/oily air out.
DCX Responds to these concerns with the following: - Thanks Breakin Newz
Straight from Darrel Cox..
"Its best to run the PCV thru a check valve to insure it from leaking while under boost.
Next the engine really benefits from the added vacuum under boost if the drivers side of the valve cover is connected back to the air intake. There is alot of vacuum there while under boost.
To insure no oil gets consumed from the air intake you install a recovery tank between the two.
This way when the car is at idle and under no boost the PCV, hence the name (Positive Crankcase Ventilation) keeps vacuum applied to the engine. When the engine is under boost the air intake pulls a vacuum on the crankcase. Bottom line vacuum all of the time. The rings conform to the cylinders better with vacuum. Also ring flutter is minimal with vacuum keeping oil from being pushed by the rings and up onto the top of the pistons and combustion chambers. Out of all of the engines we have disassembled over the years you see it every time (the ones that are not connected to the air intake) also remember that engine oil added into the combustion process greatly reduces the fuels octane. This can causes unwanted detonation and spark knock. The crank seals, valve seals, and cam seals are designed around this vacuum. Also this greatly reduces windage in the crank case further adding proper oil control and some added performance."
ACTUAL PHOTOS W/STOCK AIRBOX
Overall Engine Shot

PCV Side with $20 Catch Can installed

PTP Check Valve and Breather-Side $20 Catch Can

Breather-side routing, top shot; Make-up filter

Breather-side Catch Can, side shot - this is where you can see the breather line running into the stock location (make-up filter)

Make-up Filter inside the airbox

In about a week I will borrow a short ram and get pictures of the proper routing with an aftermarket intake.
Feel free to post questions or comments!