Ok guys I am an idiot. I have the catch can mounted, but not sure where all the lines go. Yes I have read the instructions in other posts, but I really need someone to walk me through which lines to plug into for the catch can on the sti. I know it's simple but I just need a little hand holding here.

thanks,
Dan

Do you want to put a catch can on the valve cover vents, or do you want to put a catch can on the crankcase vent?

What do you plan to do about the PVC diagnosis connector/sensor between the PVC hose and the intake duct? It appears to be a new sensor in the 2004 turbos (WRX and STi). I asked earlier on what to do about that thing but nobody seem to know. See http://forums.nasioc.com/forums/showthread.php?s=&threadid=397033&highlight=greddy+catch and http://forums.nasioc.com/forums/showthread.php?s=&threadid=398599 . There is a link to the way it should be installed for the 2001-2003 in the first link.

What to do?:(

Thats the problem. I have this catch can and not sure how I can use it.. I know guys have installed them on the sti. Not sure the best way to do it. The pvc thing does provide a bit of a problem.

Originally posted by dlowman
Thats the problem. I have this catch can and not sure how I can use it.. I know guys have installed them on the sti. Not sure the best way to do it. The pvc thing does provide a bit of a problem.

I have pictures of my Perrin catch can here.

http://home.kc.rr.com/cerberus

hey Hummer,
What gauge set is that on the dash, and where can you get it. looks great!

Originally posted by WagonDave
hey Hummer,
What gauge set is that on the dash, and where can you get it. looks great!

Thanks. I got them from Jspec here.

http://forums.nasioc.com/forums/showthread.php?s=&threadid=332044&perpage=25&highlight=omori&pagenumber=12

Originally posted by Hummer


I have pictures of my Perrin catch can here.

http://home.kc.rr.com/cerberus/STi.htm

Nice exhaust!!! Titanium, right? What kind of gain did you see? What exhaust is it? Any difficulties fitting it in? Thanks!

I see that you caught the crank case vent but did not hookup the PVC vent. That's the one I'm having all the questions about.

Originally posted by StiDreams
I see that you caught the crank case vent but did not hookup the PVC vent. That's the one I'm having all the questions about. You can't tell from the pictures what Hummer has done with his crankcase vent. It looks to me like he has installed the Perrin catch can as a valve cover vent catch can, and that his crankcase vent has been left alone.

My apologies, I used the wrong terms. The catch can is "usually" installed to catch the valve cover and PVC ventings, not the crankcase. I should edit my other post for correct terminology. In any case, there is still the problem about the PVC diagnosis connector/sensor.

Originally posted by StiDreams
My apologies, I used the wrong terms. The catch can is "usually" installed to catch the valve cover and PVC ventings, not the crankcase. I should edit my other post for correct terminology. In any case, there is still the problem about the PVC diagnosis connector/sensor. If we talking in correct terms...

There is no PVC. It's the PCV. Positive Crankcase Ventilation. Vapors from the crankcase can produce just as much oil in a catch can as vapors from the valvecover vents.

Go disconnect the sensor connector on your PCV, hook up an OBD2 scanner or DD, and report the code that is thrown.

Sorry, PCV. I agree that the crank case vent can produce just a much oil as the valve cover vents. I'll disconnect it and see if it thorws a code. I'm pretty certain it will. The question is how do you defeat this thing. I corrected my other threads to reflect the correct terms. Read them and see if you think that one of the solutions that I was looking at seems reasonable.

hey dlowman,

Did you ever get that thing in there? Did you end up doing just the valve cover vents like Hummer? Or did you do the PCV also? If so, how did you get around the PCV diagnosis connector/sensor?

Originally posted by StiDreams
In any case, there is still the problem about the PVC diagnosis connector/sensor. The PCV Diagnosis Connector -

DTC P1491 — POSITIVE CRANKCASE VENTILATION (BLOW-BY) FUNCTION PROBLEM

Disconnecting/removing the PCV Diagnosis Connector will result in a MIL illumination from a P1491 code.

The PCV Diagnosis Connector detects blow-by hose release abnormality. A 1491 code is thrown when the diagnosis terminal voltage is high. The PCV Diagnosis connector is a 5 volt sensor.

Originally posted by Austin
The PCV Diagnosis Connector -

DTC P1491 — POSITIVE CRANKCASE VENTILATION (BLOW-BY) FUNCTION PROBLEM

Disconnecting/removing the PCV Diagnosis Connector will result in a MIL illumination from a P1491 code.

The PCV Diagnosis Connector detects blow-by hose release abnormality. A 1491 code is thrown when the diagnosis terminal voltage is high. The PCV Diagnosis connector is a 5 volt sensor.

Hey Austin,

Thanks for the info. What do you think about my idea of:

1. PCV to Diag sensor to T, valve cover vents to T, T to can, can back to valve cover input to intake duct, and cap PCV's input to intake duct.

or

2. Same as 1 except go into PCV's input and cap valve cover vent's input to intake duct.

or

3. PCV to T, valve cover vents to T, T to can, can to Diag sensor into intake duct. and cap valve cover vent's input to intake duct.

or

4. Cap off PCV's input to sensor. Do the can mod like before. PCV T to valvec cover vent to valve cover input to intake duct.

or

5. A can with 2inputs and 2 outputs. Essentially 2 cans.

I don't have a can yet. I wanted to use the Greddy one but I'm having a hard time sourcing one with 15 mm. In any case I think I'm going to do #4 and if that craps out, I'll try #1. Hopefully one of the above solutions will be able to avoid the MIL you mention or any other for that matter. When I get a can, I'll update.

Don't try to tie your valve cover vents to the crank vent. Use two catch cans. Crankcase blowby gas scavenging is much more inportant than the rocker covers.

For the valve covers, I'd just run them both into a vented can.

For the crank vent, make only one change - route the hose from the T to the induction pipe differently. Route that hose from the T to the catch can, then from the catch can back to the induction pipe. The hose that goes from the T to the PCV valve - leave it alone. Leave the PCV alone.

Hummer:


I LOVE those STi plates inside the door jams- real slick.

Where can I get some?


//Brian

Originally posted by SportyBry
Hummer:
I LOVE those STi plates inside the door jams- real slick.

Where can I get some?
//Brian

http://www.rallispec.com/

Update......I had a Perrin turbo inlet put in three days ago and it does not have a PCV intake. I routed the PCV and valve vents together to the Perrin catch can. It is working great so far {No CEL}

More info here
http://www.imprezawrxsti.com/postnuke/modules.php?op=modload&name=PNphpBB2&file=viewtopic&t=2552&sid=5efca66da85dab1f5b03ecdb18e09aa0

Pictures here
http://home.kc.rr.com/cerberus/pcv_and_valve_blow_by_reroute.htm

OK, we've tried this mod today and I can finally understand the reasoning for the PCV Diagnosis Connector but...

could someone please draw or layout the connections in layman's term - a pic is ALWAYS worth a thousand words.. :D

Thanks!

I looked at the pics on Hummer's site. The way it looks is:

If you look at the PCV you will see that right up against it is a "T" (PCV factory "T") with 2 hoses comming from it. The skinnier one runs underneath the BOV hose to the intake manifold somewhere. Leave that one alone. The bigger one comes from that "T" (PCV factory "T") and gones to the sensor which is on the turbo intake duct. That's the side that will be "T" (catch can "T") together with the valve cover vent. Hummer said that he dremeled the input to the factory turbo duct off along with the sensor. He put a hose from the sensor and "T" (catch can "T") that together with the hose from the joined valve cover vent and ran a hose from the "T" (catch can "T") to the catch can. From the catch can back to the input location at the turbo input duct for the valve cover vent. He did not have to cap off the input for the PCV because he replaced the factory turbo inlet with a Perrin one. The Perrin one does not have a inlet for the PCV. I'm going to do the same but I will try to remove the sensor from the factory turbo inlet instead of dremeling it off. If that doesn't work then out will come the dremmel.

recap: from PCV to sensor to new hose to "T" for catch can. From joined valve cover vent hose to the "T" for catch can. From the "T" for catch can to the catch can. From the catch can back to the turbo inlet (original location for valve cover vent).

I looked at Hummer's personally this weekend and while I think your ideas will work....would this be easier/possible?

That hose that comes up to the sensor/input....can we cut that hose, run the PCV side up and splice it into the 'input' catch can line and then just splice the 'output' catch can line back to the input side of the PCV sensor? That would allow you to leave the sensor/input in place, keeping the CEL off, but still 'catching' both valve and crank vents.

Can you guys explain what is the main purpose of a catch can, and why it is good to have? From what I can come up with, it runs air some kinda air lines from air that escapes via valves and some other parts to upper parts of an engine, and when rpms go up it can push some oil there and have it sucked through lines, but where the lines end up? I just wanna justify spending some buck on useless, no-go mod mod? So if it helps keep engine clean, I might get one.. lecture me please :disco:

Grap on my what?


Perrin's site explains it pretty well. Your post made my head hurt.

http://www.perrinperformance.com/products/catchcan/catchcan.html

I installed a Perrin Oil Catch Can on my 2004 WRX yesterday with no problem. The directions state:

1) Cut the inlet hose to crankcase vent tube (fat hose) after the hose makes its right turn. (Cut where the hose is running parallel to intercooler.) See picture below.
2) Turn the hose connected to the inlet tube toward the right side of car. Now both cut ends point toward driver's side.
3) Insert the 1/2"-3/8" connectors into each cut hose.
4) Attach the catch can hoses to these two connectors and the other ends to the cath can nipples.

I don't see what the "sensor" problem would be with this install? All you are really doing is "adding length to the stock hose" with a catch can in the middle?

What am I not understanding here?

http://www.mandia.com/wrx/catch_can.jpg

Originally posted by links_courses
I installed a Perrin Oil Catch Can on my 2004 WRX yesterday with no problem. I don't see what the "sensor" problem would be with this install? All you are really doing is "adding length to the stock hose" with a catch can in the middle?

What am I not understanding here?



You are not routing your pcv vent oil to the catch can. There are two vent lines and you are only catching the valve blow by.
http://home.kc.rr.com/cerberus/images/Reroute.jpg

More info and pictures here.
http://home.kc.rr.com/cerberus/pcv_and_valve_blow_by_reroute.htm

Anyone figure out a clean way to defeat the sensor and still use this perrin catch can?

I dont know if this would work but I have a supra TT and i know that when people remove the EGR valves it throws a check engine light. People fix this by inserting a resistor in the circuit and tricking the computer into thinking everything is stock. I think the same logic would work on this sensor you would just have to figure out the correct ohm resistor to use. Here is a link to the mod on a supra if it will help anyone out.
http://www.mohdparts.com/egr_mods/defeat/index.html

Reply from Perrin

I sent an email to Perrin asking why their catch can only vented the valve cover and not the crankcase. I also pointed them to this thread. Here is their reply and they said I could post this to the boards:

Scott,
About the hose routing, yes there are 2 different hoses to route to the can, the valve cover hose and the crank case hose. Both of these emit the same type of vapor, which can run through the catch can. We don't tell people to hook it up to the PCV or crank vent for 2 different reasons.

First understand that coming off the crank vent, is a tee that goes to the PCV, and to the inlet pipe.

1. the PCV hose pulls too much vacuum that can cause issues, (emissions related, and other things) so capping off this one is not good, nor is capping the other vent.

2. the vent the goes to the inlet pipe can be hooked up, but we don't supply the parts to do so, because our inlet pipe comes with the hose and tee to do so.

Definitely don't cap off one or the other, or both, that can cause your engine to ingest oil and it will cause too much blow by.

Vacuum from the PCV directly, is good for your engine. It helps the engine "breath" while coming off of boost and under idle conditions. NASCAR uses separate vacuum pumps to help with this "breathing".

If you would like to hook up the crank case vent (the hose going to the inlet pipe, not the PCV), you will need to get a 1/2 tee and some hose. Then you can run that hose into the valve cover vent hose that already is hooked to the catch can. Just make sure you don't block off the PCV, or hook that up to the can.

Also the vapor and oil that gets sucked through the PCV is
introduced into the manifold after the intercooler. So there is no risk of oil getting into the IC, and IC pipes, which will cause the IC to be less efficient.

This is always hard to explain via email.

Jeff Perrin
PERRIN Performance
503-643-4677
www.PERRINPERFORMANCE.com

First understand that coming off the crank vent, is a tee that goes to the PCV, and to the inlet pipe.

1. the PCV hose pulls too much vacuum that can cause issues, (emissions related, and other things) so capping off this one is not good, nor is capping the other vent.

2. the vent the goes to the inlet pipe can be hooked up, but we don't supply the parts to do so, because our inlet pipe comes with the hose and tee to do so.


So, from what I understand, we can hook up the hoses that go to the inlet to the catch can? I hooked up the vents that go through the tubes in the IC, and the tube that goes from the PVC tee (the one that Mr Perring is refering to ) to the intake. Is this other hose re routing going to cause problems? Car doesnt feel bad, but I can feel more the engine.

I installed a Perrin Oil Catch Can on my 2004 WRX yesterday with no problem. The directions state:

1) Cut the inlet hose to crankcase vent tube (fat hose) after the hose makes its right turn. (Cut where the hose is running parallel to intercooler.) See picture below.
2) Turn the hose connected to the inlet tube toward the right side of car. Now both cut ends point toward driver's side.
3) Insert the 1/2"-3/8" connectors into each cut hose.
4) Attach the catch can hoses to these two connectors and the other ends to the cath can nipples.

I don't see what the "sensor" problem would be with this install? All you are really doing is "adding length to the stock hose" with a catch can in the middle?

What am I not understanding here?

http://www.mandia.com/wrx/catch_can.jpg
Nice engine just got perrin as you, haven't installed and going on web to find out to get all base hits. looks like you are not veniting the crankcase vents that from passenger side into catch can. Rumor has it to do this right and not induce oil vapor into system you need another C/C to vent the crankcase vent line into inlet tract of turbo.

you can use one can for both.....i think i posted a pic a while back

Here is my custom dual catch can install. Right now I only have the breathers hooked up. I still need to get the PCV hooked up and will have that done soon.

http://www.bescaredracing.com/sti/catchcans/install/cans/DSC02007.JPG
http://www.bescaredracing.com/sti/catchcans/install/hose/breather/DSC02053.JPG

My setup didn't harm any stock hoses on the STI so far. Everything is completely reversible. The bracket used to hold the cans to the side of the strut tower uses existing holes. No drilling.

My full install diary in case anyone might want to follow what I did can be found here:
http://www.imprezawrxsti.com/postnuke/index.php?name=PNphpBB2&file=viewtopic&t=17601

t

wolfplayer, thats insanely detailed and sharp looking! Hats off to you!

Looks like I know where I'm getting catch cans!

Thanks a lot!!

GGT

btw you need 2 oil catch cans to make it really worth ure while

btw you need 2 oil catch cans to make it really worth ure while
not if you replumb everything. :P