I have been lookin around for a new Y pipe because my last one was a POS (WSP). I cant see a difference between the fed spec and the cali specs for teh 4th GEN. Is there a difference and what is it?

 

This is what the Cali spec looks like...


The Fed-Spec has the full bend to the front header.

 

Cali spec is designed so the third (extra) precat remains.

 

How come mine did not look like this? Mine had the full bend on it like the FED SPECS. It fit fine too. I have a cali spec car....................

 

Not quite, the Cali Spec pipe keeps both front pre-cats in place. It doesn't remove anything, it's designed for better/smoother flow of your exhaust system.

 

So you wont get nearly as much gains as you would with a fed spec car? I thought maxs only had 2 precats.

 

this sucks cuz i have a cali spec n i plan on getting a cattman through the group deal..how hard would it be to do a fed spec conversion?

 

not hard at all, just changing out one pipe for another. I need to do the same thing

 

oh so i can just get a fed spec pipe and it will fit with out a problem?

 

To use a fed spec y pipe you just need to get the front fed spec exhaust manifold and then wire up some O2 simulators to fool the O2 sensors that look for the precats.

 

thats what i did.. made my maxima louder..

 

with my budget y pipe it came with a grey gasket similar to the one in that picture at the beginning of this thread.
i installed it between the cat. and the y pipe. i got a high rasp whenever i'd get to over 6k rpm and i assumed it was the replacement gasket. when i was installing my greddy sp2 I noticed the "gasket" i put in there was whitish in color. it looked like it got too hot and caught fire briefly or burned or something. the y pipe is also discolored around that area. i saved the "gasket" that was there with the original y pipe which is more like a couple thin pieces of metal. i put it back in there and the sound issue seems to have disappeared (hard to hear over the sp2 though to check)

however! whe ni went to autozone looking for a replacment gasket he told me the STOCK gasket (metal sheets) were actually spacers.
anyone know anything aobut this?

 

Huh I prototyped the 1999.5 CA NLEV Y for Warpspeed and it does indeed remove the pre-cat which is physically part of the stock Y-pipe (rear pre-cat)... The front 3" pre-cat remains though...

The gains are pretty much the same when adding a Y to either a Fed spec or a Cali spec (12-16whp). I am not 100% sure of the pre 99 Cali spec but the 99 has 3 cats (two pre-cats(one part of the Y and one part of the front manifold) and one main cat).

The 99 has a totally different Y pipe made for it and the fed spec pipe will not work...

I will be replacing my stock front manifold with a 99 fed spec this spring along with a new fed spec Y.. I will also be doing the 00VI with EMU(if they work the bugs out of it).

 

No, the cali spec y pipe removes the 2 precats in the y pipe but is designed to accomodate the third extra precat in the manifold. Look at the pic posted by mtri760.

 

My CA SPEC has TWO 02 Sensors for the Y pipe>>>>>>????????????

 

your cali spec has a total of 4 o2 sensors. two before each pre cat, and two after each pre cat.

 

It may be true that the pre 99 Cali spec Y-pipe removed all pre-cats and left just the main cat, but on the 99-00 it is not. The 99-00 CA NLEV pipe leaves the front 3" pre-cat, removes the rear pre-cat (which is integrated into the Y-pipe), and leaves the main cat. Also none of the Y-pipes that I know of remove the main cat, to do that you would need a test pipe.

 

which is also illegal to do. Any respectable shop will not remove the main cat, some wont do a y-pipe switch, the fines for cat removal are obscene!

 

the 99 cali spec does not remove all of the precats. it leaves the one in the manifold... no one ever said anything about it removing the main cat.

 

Is there a performance difference between these two pipes due to design of the closer arm of the Y? (where it loops around)



You can see it loop around before it attaches to the header...
I thought I read somewhere that the car runs smoother, or something due to the exhaust traveling the same distance out of the car?

 

You cannot compare Y-pipes to headers. Headers make more power, Y-pipe is the alternative. Its comparing apples to oranges. You just have to decide if you want to spend $300 for a Y-pipe, or $600+ for headers.

 

I was not. It was just the first pic I found with the ypipe like that where both Ys are equal length instead of the one closer to the rear of the car being shorter.

 

I have a 99.5 Cali-spec car.
I have the Warpspeed Y pipe.
I installed it myself.
I removed no pre cats when I put the pipe on.

DaEnigma - The prototyped pipe you may have tested never went into production. I actually spoke to them about that pipe over 3 years ago. I wasn't happy with leaving only 1 pre cat on the car. That makes one cylinder bank slightly more restricted then the other one. I didn't like that idea so I didn't buy the pipe until the design was changed to leave both pre cats on the car. You can verify that if you call Warpspeed. The reason for that was an O2 sensor location issue.

 

strange.... i wonder how you can keep both precats and add a y pipe.. do you have a picture of this?

 

I had the same question as the first post... so if you life in cali i assume u must use cali spec or can u still pass emisson test if you have fed spec? I am about to get a whole exhaust system for my 98 max and obviously i want to make sure i can pass emisson law any help would be awesome thanks.

 

The pipe I prototyped is the one that went to production they made the jig from my stock pipe. I was one of three people who did the prototype for WS you can call and ask again if you like.

If you removed the stock Y-pipe then you removed the rear pre-cat... It is physically part of the stock Y-pipe (the oval bulge below where the rear manifold connects to the Y http://www.greghome.com/images/Maxim...Comparison.jpg)...


http://www.rockauto.com/ref/Walker/Detail.html?1090.gif
Look at the pic see the two front precats? On the 99 CA spec the front one is moved into the manifold and is increased in size to a 3-4" diameter precat but the small second one stays right where it is...

I dont mind being wrong and I have been before so if you can show me otherwise that would be fine with me...
Here is more information on the CattMan prototype which has great pics...
http://www.greghome.com/Greg's%20Gar...S%20Y-Pipe.htm

 

If the rear pre cat was removed, the O2 that monitors that cat (cali Spec emissions)must either be moved to look at the front pre cat or simulated so the ECU doesn't throw an error code. That was an issue at Warpspeed for us Cali Spec owners.

The pipe looks exactly like the picture posted above, but that rear connection is indeed bolted to the bottom of the rear pre cat, not the manifold. The front pre cat O2 sensor bung is clearly visable on the straight section of pipe, the O2 for the rear pre cat is on the other side of the pipe facing away from you in that picture. Basically both o2's are in the exact same positions as the stock pipe and they both monitor exhaust after each pre cat to make sure they are working correctly.

You must maintain the 4 O2 sensors in a cali spec set up. They must monitor exhaust just before the pre cats, and immediately after the pre cats. The pipe they were working on was supposed to remove one pre cat, the rear, and provide a place after the front pre cat to put the rear O2 sensor, tricking the ECU into thinking it was monitoring both pre cats. Believe me, the Cali Spec pipes which they are currently selling does nothing of the sort. It simply provides a smoother 2 into 1 transition over the stock set up. Trust me, I have that pipe installed on my car.


EDIT:

I just wanted to go over another option for Cali Spec owners. You can install a Fed Spec pipe on the car. This is accomplished by removing both pre cats, they unbolt from the manifolds. Then install a Fed Spec pipe, it should bolt right onto the manifolds where the pre cats where. Next get a duel O2 simulator to get the signal for both sensors and wire that into your existing O2 harness. That keeps the ECU happy. That set up will give us the HP increase most 4th gens experiance with a performance Y pipe set up. Unfortunately the Y pipes for Cali Spec cars don't give us any large noticable increases, but hey anythig helps.

 

Normally I would just say WTH and not even care about this, but the information about the Y-pipe not removing the rear precat is incorrect. I have said this so many times it hurts but I will say it again. If you have a CA spec 99 and remove the stock Y to put an aftermarket Y on then you have removed the rear precat... because it is physically part of the stock Y!

Here is a pic of the rear manifold
http://www.greghome.com/images/Maxim...r_Manifold.jpg... and no cat is to be found because like I said it part of the stock Y-pipe and it can not be removed from the pipe that I can see either...

Here is a pic of the front manifold/precat http://www.greghome.com/images/Maxim...rd_Pre-Cat.jpg this precat can be removed from the manifold but the flange is so odd that not one of the suppliers even wanted to attempt a fitment... Also note that the front precat rear O2 sensor is mounted vertically here usually you can not see it behind the heat shield. There is also another O2 which can be seen from the engine compartment which is the front precat front O2

And here is another pic of why the rear O2 sensor does not throw a code... http://www.greghome.com/images/Maxim...connection.jpg it is right behind the front precat so it heats nicely...

The O2 sensor you are looking at right here http://www.greghome.com/images/Maxim...complete_1.jpg is the O2 that usually connects behind the rear precat if you look closely at the second pic I posted you can see the front precat heated O2...

So from the front manifold to Y collector we have O2---->O2---->O2. Then from the rear manifold to the Y collector we have O2 making a total of 4 O2 sensors. Now to rid yourself of the front precat all that needs to be done is relocate the two heated O2's which are behind the large front precat to behind the main cat, replace the front manifold with the Fed spec manifold, and replace the CA Y with a Fed Y.

 

So in laymans terms. We need to drill two holes in the b-pipe and screw the two heated O2 sensors in. Then purchase a fed spec ypipe and purchase a fed spec front exhaust manifold? So in the end we go from 4 O2 sensors down to 2 right? We should still have to trick the ECU into thinking there's four too, correct?

 

OK, I just went out and took a good look at my old factory Y pipe. AND I have to come clean here and stand corrected. DaEnigma is indeed correct with the fact that the rear pre cat is indeed part of the old pipe. Sorry for the confusion here guys.

 

By putting the two heated O2 sensors behind the main cat you have tricked the ECU into thinking they see the high temp from the precats when in fact they only see the main cat.


I appreciate your statement and thank you. But please keep in mind that I was not trying to prove you wrong. I was trying to just make sure the community has the correct information.

 

100% with you on that one!

 

I know its been settled but here for future use....

 

Pulling this thread up since I finally decided to install my WSP Y-pipe this weekend...

FYI, I have a Cali-spec car and it appears WSP shipped me a Fed-spec pipe over a year ago when I ordered it. Didn't realize what I had at the time, and only now have I peeked at the setup and removed some of the heat shields.

I was considering doing that except I seriously doubt it will bolt up to the manifold. The front bank's precat-to-manifold connection appears to have roughly 5 (?) bolts, and the connection looks large. Am I to believe that if I removed that, there would be 3 bolts and holes that would line up perfectly to the 3-hole WSP fed-spec front pipe connection?

EDIT-
Nah, no way that's going to happen. That manifold-to-precat connections looks nothing like the Y-pipe front connection and it's a lot larger.

 

get a fed spec front manifold.. simple enough..

 

WSP said they'll take it back and send me the right one, so I'll do that for simplicity sake.

 

Im bumping this thread because 1st this is very informative for those who dont like to search, second it came up with a purchase Im involved with.

 

mine looks exactly like that i a cali spec

 

Thats why I bumped this old thread, I think it is very informative, my y pipe is different, I still have'nt talked with my friend yet but I'll see him this weekend and get back to you.

 

Good lord talk about back from the dead!