02whitemaximase

iTrader: (38)

The OBX headers (02-03 Maxima, equal length y) have been out of stock for at least a year. They are finally back as of late December 2011. I am going to install them in the next week or so. For engine performance mods I have the Megan OE-RS catback installed along with berk/apexi intake and 5 piece spacers. I have compiled all of the information needed to get these headers installed correctly.

The headers are going to arrive this Wednesday. I plan on posting a few pictures of them out of the box. I have a feeling that these may have some differences from the past version 3. A few drawbacks for the previous OBX headers is the weak flex section, y-pipe past the collector being a measly 2 1/16” diameter, poor primary oxygen sensor bung placement on the rear bank, and the alignment issues which call for trimming the cross member and rear motor mount bracket. I hope that this newest batch will have addressed some of these issues. I also have a feeling that the y pipe diameter has been changed to 2.5” which is great news.

It has been confirmed! It is about 2.5" for the y pipe.

My first photo is of new OEM exhaust gaskets. Look at the part numbers and order those if you plan on doing a header install on a 3.5. Although you could get away with reusing the original gaskets, I would recommend spending 35 bucks for the peace of mind.

The front (closest to radiator) header measurements are as follows:

Runner length from where it meets the flange to where all three join
cylinder 2= ~10", 4= ~9" 6= ~12"


Prices and part numbers:
OEM exhaust header gaskets $13 each 14035-4W015
OEM cat gasket $8 20692-65J00
Spark plug antifouler $5 each pack made by HELP 42009, 42002
MAF cleaner $7
Energy Suspension (ES) subframe bushings $25 7.1116G
OBX 02-03 headers $350-380 shipped


The purpose of this thread is to display the newest batch of OBX headers. Exhibit how the install goes and post up some before and after pictures and videos.

Please feel free to ask questions or post comments. I will be happy to take requested pictures.


The rear header/y pipe is currently getting the primary bung relocated and a new wideband bung added. I will have them back tomorrow and will amend this post again thereafter.

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Installation Notes
My install went nearly flawlessly minus one heat shield bolt being seized and a secondary o2 sensor not coming out of the old converter. I know these headers are made over seas where quality control is not great. With that being said I think no two sets of headers are exactly the same which means that you may need to trim something during your install. I came a couple of millimeters from having to trim my front motor mount bracket and my rear bracket went on no problem although it was very close. Probably about 2-3 mm from touching and my front bracket is literally 1mm from touching the header. My flex pipe has about 1/4' space from touching the subframe.

As you can see one of the primaries comes very very close close to the front motor mount bracket but it did not require trimming. Although some may be uncomfortable with how close they are, it is no problem. The mount and header will NOT move even though mine are basically touching it does not matter.


The y pipe comes about 1/4 of an inch from touching the sub frame cross member. Again this is not a problem. I have driven it like this enough to not experience any noise and the way I see it the motor really only moves front to back so this tight space does not come into play.


In order for the front primary to have enough wire slack to reach the new header bung you will have to cut the tape holding the group of wires that travels directly over the middle coil from the larger harness that runs along the top of the valve cover. The tape was holding both harnesses together to about right in the middle of the top middle of the valve cover. Easy fix takes one second.


As you can see below the far left plug has to be unclipped from the coolant pipe in order for that primary to reach.


The rear primary wire has to be extended too. From all of my research people here have been saying to cut the primary either at the wire harness and add some wire to lengthen it or to cut the actual o2 wire and extend those by adding wire. Problem is that is can mess with the voltages. The wire is stainless steel which is nearly impossible for an amateur to solder correctly. My method requires NO WIRE CUTTING!!! You need to remove the wire harness cover pictures below and simply separate the o2 wires from the rest of the wires. First you need to separate is from the green plug wires, then you need to slit the right side of the main harness that fees into the back of the plastic box. PLEASE TAKE YOUR TIME!!! Be very careful to cut precisely and slowly. Doing this will give you enough slack to reach the rear primary o2 sensor.


This next pictures shows exactly where my o2 wire is coming out of the main harness. It is wrapped in a black plastic protector. This picture is taken along the firewall from the driver side, so the top of the picture is the passenger side, the bottom is the drivers side and as you can see the top left is the upper part of that black wire harness box. The fattest harness coming from the box is what you need to slit the side of and separate the 02 wire from. My o2 wire is running out of that harness down toward the middle of the picture.


The following picture is of one of my secondary sensors. I have the antifouler setup and as of about 75 miles no CEL. This secondary is the one with a green plug and red wire cover. The wire running above it is actually the other secondary which is the blue plug with white wire cover. I secondaries have different length wires so I recommend this configuration
.

aackshun

iTrader: (3)

Take measurements of EVERYTHING!

02whitemaximase

iTrader: (38)

Will do. Can't wait to wrap a string around the primaries and y pipe. It's been too long since I have had to use pie.

cjandura

iTrader: (3)

Dont know what you USING a pie to do.but just slapping a ruler across the end of the pipe will measure it just fine.
Wonders if People on the ORG have a strange PIE fetish??

02whitemaximase

iTrader: (38)

diameter=2[c/(2pi)]

rulers are boring

AznRyan

iTrader: (1)

I'd use the ruler and eat the pie.

Jason R

iTrader: (39)

Very nice! Can't wait for the detailed pics of these headers since i've been thinking about a set for my car.

Xpcgamer

iTrader: (5)

Thank you for doing this. I spoke with the Header dude at OBX and he told me they where the same. I did ask specifically on the 2 piece vs 3 piece design and he said they where 2 piece. Keep us updated. Was planning on gutting the cats and buying a WS Y pipe but the cost is almost to the price of the OBX. Subbed.

schmellyfart

iTrader: (46)

Also, why not use a caliper to measure the pipe?

02whitemaximase

iTrader: (38)

No caliper in my tool collection.

02whitemaximase

iTrader: (38)

This is an actual picture of the headers from the vendors posting. That y-pipe looks thicker than other pictures from the old versions.

Xpcgamer

iTrader: (5)

Looks promising!

aackshun

iTrader: (3)

They look like mine.

essential1

iTrader: (5)

Looks just like the set I helped a friend install a while back. I'm willing to bet money that its the same exact design as the previous. Obx is all about keeping manufacturing costs down. Bigger diameter/thicker piping will drive that cost up significantly which in turn will make the price the consumer pays multiply by god knows how much to offset the difference.

dnice02

iTrader: (1)

Nothing changed. I installed mine last week Saturday. The inside diameter is not 2.5on the y pipe. You still have to relocate or use the next bung down for the rear primary. I still had to grind down the cross member and front motor mount, and take the little cover off of the rear mount. Other than that the install went ok i guess. Oh and its still a 2 piece design.

7speed

Thats too bad. I was hoping it would have been corrected because I thought about selling my cattman y to get the obx combo. But looks like I'll just have to keep the ypipe and keep working on this project.......

CMax03

iTrader: (3)

Sell the Cattman and Go OBX! I'll take the Cattman off your hands! You'll awaken out of this dream into a freaking nightmare the day you sell that Cattman for OBX......

S.O.S.;......why change it? It might be even harder to install if they did.......

Yeah Good luck too all you OBX Lovers.....

JonBlz

iTrader: (11)

gutted out my cats as well and paired it with a full exhaust and definitely runs hard

TDMIIG

I pulled the trigger on a set of OBX headers last night. I'm looking forward to the install (once it gets warmer). I installed a set of headers on my acrua CL-S so I'd hope this isnt too much more difficult. I'll photo document the install. I may get a warpspeed hfc while I'm at it.

dnice02

iTrader: (1)

I kinda miss my gutted cats. I didn't really notice a power increase going from gutted cats to headers. But it could just be me.

cjandura

iTrader: (3)

looks like the same design as the ones i got last year.ended up smashing them on the ground and slinging what was left across my driveway after 6+ hours of fitment issues.

ranmas2004

iTrader: (2)

Nothing against OBX but I just consider it poor engineering if you claim this part fits and people have to cut and grind pieces off their car just to get it to fit. Thats unacceptable! they have been selling these things for years and STILL have not improved them??? I'm sure many people have let them know and they REFUSE to make improvements.......thats just horrible. As I said nothing against people who have OBX headers and they may perform great once installed, but purposely not changing your product after you know there are serious fitment issues is just terrible.

schmellyfart

iTrader: (46)

They don't have much incentive to change the headers since people are still buying them with the issues.

ShocknAwe

iTrader: (3)

GL on the install. WHen a friend ordered the pair we took a look at it and just sent it back. They aren't exactly Ebay cheap and you should NOt have to do all this modding and grinding to make them fit. Even if they changed the design the cost would go up as others said and who knows if they would even fit better? maybe even worse. They aren't a bad product and certainly show gains in WHP and torque but they need to be redesigned as far as fittment goes. They know of the issues, as I as well as hundreds of others have told them and they haven't corrected a damn thing which is far from good business. I lucked out and found a Cattman which is far from the norm and the install went as it should for a pricey item. We are stuck with OBX now as Cattman slips into the abyss.

aackshun

iTrader: (3)

It took me 10 minutes w/ a sawzall and dremel.

cjandura

iTrader: (3)

NO! just Old and inpatient! oan i would do all the modding before trying to install first get 2 new O2 bungs and have them welded 90* from their current location then plug the orignals also i would get a small 4" long good quality 2.25" lined flex section and cut the rear header off and install the flex to better aide in movement and alignment.but thats just my opinion from what i went thru.

ShocknAwe

iTrader: (3)

Just cheap lol. If I pay for a direct fit product it should be direct fit, not half *** fit with some mods. If Cattman can do it then OBX can do it. Not like it would take a million dollar research team to fix it. They probably have the issues with pictures in their inbox as we speak because EVERYONE will have these issues when they install them. I helped another friend install them who didn't care that it would take longer and it took us about 6hrs to do it with quite a few smoke and beer breaks mixed in. Not HARD per say other than the obvious difficulty with the rear header but just unnecessary for a product thats marketed as direct fit.

aackshun

iTrader: (3)

I didn't relocate them, I only have two o2s

Just extended the wires on one.

Lets see....

Extended Wires ($5)
Took a sawzall and dremel to the xmember (upon initial initial install I did not have clearance issues but then I got the solid mount and then I did). ($meh)
Brought two oil drain bolts from lowes ($5)
Had a new Flex Section Welded ($80)

OBX Headers Shipped + Mods = $470, and I got them after 3 business days.....

Happy OBX customer here.
Sure.... WHEN you pay for direct fit. In OBX's case, you did not, so your point is now moot.

cjandura

iTrader: (3)

I would of modded mine to fit but the damn header flange broke at the center exhaust tube but then again i was fully fustrated and think 80's heavy metal guitar smash as a picture of what i did to them.

02whitemaximase

iTrader: (38)

Let's not turn this thread into another OBX v. Cattman pissing match. I created it to post new numbers and answer any concerns regarding this latest batch from OBX.

NmexMAX

iTrader: (22)

We thank you for the info you've already provided and look forward to the install.

This thread might need a clean-up.

02whitemaximase

iTrader: (38)

Great news. Just got the OBX headers in. I took a ruler to the y pipe outlet and the pipe diameter is just about 2.5". Maybe a sixteenth short. I will post pictures after work.

GREAT NEWS!

CMax03

iTrader: (3)

Honestly,...... Sometimes you'll need to make adjustments when modding that's what aftermarket performance parts bring to the table these days! My hats off to those willing to install OBX and conquering all the obstacles that you're faced with! I've install many different brands of headers and every single one of them have something you have to do to make them work or fit properly....So it separates the real technicians/mechanics from the not so talented weekend warriors! I think what everyone needs is, to have a plan and stick too it, make whatever adjustment you need to make your headers work flawlessly and be happy.....Words of wisdom from believe it or not CMax03!!!!!!

cjandura

iTrader: (3)

Your really going to want to relocate that front O2 sensor because with the extra length of the anti foulers it might just poke the rad.

02whitemaximase

iTrader: (38)

antifoulers are only for the secondaries which do not exist on the front header

CMax03

iTrader: (3)

That's not necessary!!!! the primaries stay active so plug in bank 2 (front) and bank 1 need to be lenghtened to plug into the next plug downstream from the rear manifold O2 bung! Plug that rear O2 bung facing the firewall and plug the Bank1 primary in the next O2 bung, keeping the secondaries plugged but placed either under the engine cover or battery tray.....then installing a dual circuit O2 Sim.......

TDMIIG

To add to that, it would be nice if they had a "non-fouler" with a y split that allowed you to plug two o2 sensors in to one bung. Then you could plug the primary o2 bung on the rear collector, plug the primary in to the first bung on the y pipe, and plug both secondaries in to the last bung (using the y-split non-fouler thing). Everything would be plugged in and with the o2 sensors out of the direct exhaust stream, maybe no SES light and no need for simulators. All speculative of course. Anyone with some fab skills could make one and test (I'd be a willing test subject ).

02whitemaximase

iTrader: (38)

This certainly would work but I am trying to get around the sim route. Sims are very hard to come by and by using the antifoulers it would be much cheaper than a sim.

TDMIIG

http://www.ebay.com/itm/OBX-Exhaust-...item1c236c8e2e

Free shipping and $349. Just thought I'd share (I just paid 379 shipped )

iBURN

Does anyone know if the new 02-03 OBX headers fit the 2000? I'm guesging they will with slight modification, but it's not like OBX's are known to drop right in.