# A.I.V Unit : Necessary? \*pic\* **URL:** \ **Category:** SON240sx Automotive\ **Created:** [February 19, 2005, 3:00pm UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780 "2005-02-19T15:00:33Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![Gonad](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/gonad/32/5481_2.png) [@Gonad](https://forums.speedlife.net/u/Gonad)\ **Post date:** [February 19, 2005, 3:00pm UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/1 "2005-02-19T15:00:33Z")
This is the boxed unit that is near the barke fluid resevoir (just above the header sheild). On bone stock engine bays, this unit has a hose that leads it directly to the stock airbox. Most ppl who put on K&Ns, simply put a breather on the hose that is left open afterwards. According to the manual, this unit basically has a solenoid that determines when to feed some of the exhaust gases back to the airbox. I’m guessing for emission purposes this is necessairy, but seeing how I had a breather to begin with, I can’t imagine needing it. As for why I took it out, well I was trying to take my header-sheild out and the shit just got in the way so I took it out… ![http://240sx.cubicdesign.com/images/misc/aivunit.jpg](http://240sx.cubicdesign.com/images/misc/aivunit.jpg) ---
**Author:** ![TM1](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/tm1/32/5517_2.png) [@TM1](https://forums.speedlife.net/u/TM1)\ **Post date:** [February 19, 2005, 4:04pm UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/2 "2005-02-19T16:04:33Z")
Mines gone… all it does is allow air to go through a check valve and help heat the cat up quicker by mixing in more air. However this check valve can sometimes get dirty and stick, and you get exhaust gas backpressure coming out your MAFS causing obvious problems… Get rid of it, and plug any lines going to it… ---
**Author:** ![Gonad](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/gonad/32/5481_2.png) [@Gonad](https://forums.speedlife.net/u/Gonad)\ **Post date:** [February 19, 2005, 4:38pm UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/3 "2005-02-19T16:38:33Z")
> [@TM](#): > > Mines gone… all it does is allow air to go through a check valve and help heat the cat up quicker by mixing in more air. > > However this check valve can sometimes get dirty and stick, and you get exhaust gas backpressure coming out your MAFS causing obvious problems… > > Get rid of it, and plug any lines going to it… :werd: I already took it out. There’s two hoses that need to be plugged in. One big one from the exhaust (ill just stick a breather on) and a thin vacuum line which I guess I’ll just plug up. Nice… ---
**Author:** ![SHIFT\_KA24DET](https://avatars.discourse-cdn.com/v4/letter/s/b9bd4f/32.png) [@SHIFT\_KA24DET](https://forums.speedlife.net/u/SHIFT_KA24DET)\ **Post date:** [February 19, 2005, 5:10pm UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/4 "2005-02-19T17:10:17Z")
There are two vac lines going to it IIRC what I did is just join them together. And No don’t stick a breather on the Exhaust hose unless you want your car to sound like a lawnmower and you be huffing exhaust fumes all day through your engine bay. ---
**Author:** ![spd-dmn](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/spd-dmn/32/5513_2.png) [@spd-dmn](https://forums.speedlife.net/u/spd-dmn)\ **Post date:** [February 19, 2005, 5:34pm UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/5 "2005-02-19T17:34:27Z")
Plus cops look for stupid shit like breathers if they pull you over under the suspicion of driving an illegaly modified vehicle. ---
**Author:** ![DarkForceJackal](https://avatars.discourse-cdn.com/v4/letter/d/b38774/32.png) [@DarkForceJackal](https://forums.speedlife.net/u/DarkForceJackal)\ **Post date:** [February 19, 2005, 8:57pm UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/6 "2005-02-19T20:57:22Z")
I’ll be removing that when I put the turbo in…c’mon Gonad, where are your huge digital pics of the uninstall? 🙂 And about the remaining vac lines, is that it? Just join them together? Like people have been saying, don’t use breathers, and you should also weld shut the exhaust portion of the AIV system if/when possible (or just weld in a new pipe section). Can you post at least after-pics? I’m curious…thanks man! 🙂 ---
**Author:** ![Sasha\_SG](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/sasha_sg/32/5477_2.png) [@Sasha\_SG](https://forums.speedlife.net/u/Sasha_SG)\ **Post date:** [February 19, 2005, 9:08pm UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/7 "2005-02-19T21:08:05Z")
mmm gold i mean bronze bronze ---
**Author:** ![rotorkami\_wa](https://avatars.discourse-cdn.com/v4/letter/r/e36b37/32.png) [@rotorkami\_wa](https://forums.speedlife.net/u/rotorkami_wa)\ **Post date:** [February 19, 2005, 9:09pm UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/8 "2005-02-19T21:09:50Z")
a breather filter on any EGR inline system or gas bypass is a $270++ ticket… weld up the hole in the exh. , plug the CAI hole or where it may be on the CAI/steup… rotaries are so much easier then this. ---
**Author:** ![Gonad](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/gonad/32/5481_2.png) [@Gonad](https://forums.speedlife.net/u/Gonad)\ **Post date:** [February 19, 2005, 9:40pm UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/9 "2005-02-19T21:40:56Z")
> [@DarkForceJackal](#): > > I’ll be removing that when I put the turbo in…c’mon Gonad, where are your huge digital pics of the uninstall? 🙂 You asked for it…I’ll post the engine bay shot tomorow I guess… ---
**Author:** ![DTS](https://avatars.discourse-cdn.com/v4/letter/d/8491ac/32.png) [@DTS](https://forums.speedlife.net/u/DTS)\ **Post date:** [February 20, 2005, 7:07am UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/10 "2005-02-20T07:07:42Z")
just rip the shit out there isnt alot to it, plug any holes. stupid aiv, dont run breathers they are just cop magnets. i run a open thing with no breather on the valve cover of my sr and no cop has said anything about it ---
**Author:** ![NeveR](https://avatars.discourse-cdn.com/v4/letter/n/e95f7d/32.png) [@NeveR](https://forums.speedlife.net/u/NeveR)\ **Post date:** [February 20, 2005, 12:20pm UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/11 "2005-02-20T12:20:44Z")
> [@Sasha (Turbo)](#): > > mmm gold > > i mean bronze > > bronze Champaign you bastard. ---
**Author:** ![Gonad](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/gonad/32/5481_2.png) [@Gonad](https://forums.speedlife.net/u/Gonad)\ **Post date:** [February 20, 2005, 12:26pm UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/12 "2005-02-20T12:26:19Z")
> [@NeveR](#): > > [quote=Sasha (Turbo)]mmm gold > > i mean bronze > > bronze Champaign you bastard.[/quote] Sandstone Beige Metallic! Anywho, yea, either I route a longer hose further down or put a breather on otherwise, my engine bay is just going to flood up with smoke. I turned it on a few min ago and that’s exactly wht I saw… ---
**Author:** ![Sasha\_SG](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/sasha_sg/32/5477_2.png) [@Sasha\_SG](https://forums.speedlife.net/u/Sasha_SG)\ **Post date:** [February 20, 2005, 1:13pm UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/13 "2005-02-20T13:13:46Z")
> [@NeveR](#): > > [quote=Sasha (Turbo)]mmm gold > > i mean bronze > > bronze Champaign you bastard.[/quote] engine valve cover boyeeeee ---
**Author:** ![DarkForceJackal](https://avatars.discourse-cdn.com/v4/letter/d/b38774/32.png) [@DarkForceJackal](https://forums.speedlife.net/u/DarkForceJackal)\ **Post date:** [February 21, 2005, 10:37am UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/14 "2005-02-21T10:37:12Z")
Thanks for the pic Gonad, that just confirmed what I was thinking…what did you do with the remaining vac lines attached to the car? Join them like Adam, leave them hanging or just plug em? Doesn’t matter maybe? Cheers. ---
**Author:** ![Gonad](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/gonad/32/5481_2.png) [@Gonad](https://forums.speedlife.net/u/Gonad)\ **Post date:** [February 21, 2005, 3:41pm UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/15 "2005-02-21T15:41:47Z")
All vac lines (the little thin tubes) are plugged up. The exhaust line I rerouted a little further down towards the header so it doesnt fill the bay up with smoke. The hose I have only goes so far so Im gonna route it down some more or see if I can bend the existing pipe or some shit. ---
**Author:** ![DarkForceJackal](https://avatars.discourse-cdn.com/v4/letter/d/b38774/32.png) [@DarkForceJackal](https://forums.speedlife.net/u/DarkForceJackal)\ **Post date:** [February 21, 2005, 11:44pm UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/16 "2005-02-21T23:44:33Z")
I see. So any driveability changes or anything since removing it? ---
**Author:** ![Gonad](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/gonad/32/5481_2.png) [@Gonad](https://forums.speedlife.net/u/Gonad)\ **Post date:** [February 22, 2005, 4:09am UTC](https://forums.speedlife.net/t/a-i-v-unit-necessary-pic/83780/17 "2005-02-22T04:09:47Z")
> [@DarkForceJackal](#): > > I see. > > So any driveability changes or anything since removing it? My car is still on stands. I haven’t noticed any difference in idle or anything when I did run it for a while. Why don’t you do it yourself and find out? It’s not as complicated.