H2 OBX Long Tube Header w/ High Flow Cat Install With Pictures

[pdxrealtor]

Ok.. Finally got these things installed and at 100%. Love the power gain, and can't wait to get a chip or tune. The low end grunt is finally there albeit nothing like a roots blower powered five liter mustang.

These tips and pics will help you with your long tube header install.

I got the OBX high flow cat system. With this system you will need the following additional items:

- 2 M18x1.5 short bolts or drain plugs. You'll plug extra O2 bung holes with these.
- 12 M8-1.25 x 30mm header bolts. I got mine from Fastenall M8-1.25 x 30mm DIN 6921 Class Class 90 Yellow Zinc Serrated Flange Bolt
- An EGR block off plate. Hummer H2 has no EGR to connect to the OBX header. Or you can do what I did.... read below.
- Spark plug wire heat shields or custom plug wires.


Soak for a few days with penetrating oil.. I used some CRC screw loose..

1) Put it on jack stands, ramps won't work. I tried it. Why? Because for the easy breezy removal/install you must remove your tires. Don't fight it, it's not worth it!

2) Remove your wheel well liners. Another must.

3) On passenger side remove the oil dipstick tube, 15mm socket. Remove the bolt. From below, through your awesome wide open access space, work the tube up and out of the hole. Drop a flanged bolt in the exposed hole- MAKE SURE IT's LARGER than the hole! Or use a rag, whatever. I used a bolt because it was non intrusive to other work or test drives.

4) Disconnect all spark plug wires at the spark plug and tuck them up out of the way. I think the only one I didn't have to disconnect was driver side front of engine.

5) Start removing those header bolts. Warm the engine up and then let it cool down a bit so it's just warm to the touch. This will help in bolt removal.

[pdxrealtor]

Shot of trying to do it with tires on - NOPE







Tires off- see how much better that is ??




Plug wires tucked up out of the way



15mm bolt to remove dipstick tube



Dipstick tube hole plugged with bolt

[pdxrealtor]

6)Take your skid plate off, and your brush guard... the one below the tranny pan.

7) Remove your O2 sensors. The only one I had to unplug was pass. side front. The rest were easily tucked out of harms way.

8) Once all your header bolts are loose you're onto the underside of the truck to remove the pipes from cat forward (if you got the high flow cat kit, which I did). There's two ways to do this. Cut it out, or unbolt everything nice and neat. Why you'd want to do the second way is beyond me. I grabbed my sawzall and started cutting. I did save 3 or so inches on each side of the cat so I can sell them. They only have 50k on them.

TIP- leave one header bolt partly bolted in, that way the headers don't fall to the ground when you remove the under car pipes. This advice is all based on the fact that you're doing yourself a huge favor and cutting these b*tches out...

The headers will come out of the bottom. If you have any height at all (jack stands), nothing goes on under the hood. It's all from the wheel well and under the car.

See my cut points in these pics, and the entire system removed shows the cut points as well.

[pdxrealtor]

9) Alright... system is now removed. Like most people you now have broken bolts to deal with. These bolts are compliment of GM and they stick in your aluminum head. If you're lucky the stud is sticking out of the head. Use vice grips or a stud remover on a ratchet. If you're not lucky the bolt is inside the head. Couple of choices.... drill it and easy out it, or research ways to weld a nut on the bolt to ratchet it out with a socket.

I had one broken bolt, drive side closest to the firewall. There was a VERY nice stud sticking out and I just happened to remember I had this bad a*ss stud remover kit from Sears. AWESOME...right?? Ya.. it was awesome until I took two turns of the ratchet and the damn bolt snapped again.. YES.. again. A second time. So this one bolt snapped twice. Second time inside the head. Great. I was very fortunate to have a buddy over with more experience in this area than I.

We had to remove the fender well heat shield, use a drill bit with a hex end so it would fit in a socket. This socket was attached to 18" of 1/4" extension in order to reach the bolt on the head. I've heard people say right angle drill to get these busted bolts out.. I don't see it. No way.

My buddy drilled the perfect hole in this busted bolt, and then used his snap on extractor to back it out. Couldn't believe how great it turned out. Check out pics of the bolt. Two pieces... the one piece is the one I busted off with my stud remover (I was literally using the strength of my thumb!) the other piece is obviously the piece my buddy rock star drilled.

I don't have any pictures of the drill setup we used, but it's no different than the ratchet setup in other pics. A lot of length and a dead straight aim. To put in perspective the drill was outside of the fender well.



Old bolt next to new bolt - Fastenall M8-1.25 x 30mm DIN 6921 Class Class 90 Yellow Zinc Serrated Flange Bolt --- Thanks NJH2!!

[pdxrealtor]

10) Alright ... easy easy from here on. You're ready to install. Start with new headers. They GO UP from underneath the truck. Don't even waste your time trying to get them in from above. This part is easy easy. I used copper gasket spray on my gaskets. The OBX kit doesn't come with stainless, it's a graphite type gasket.

Install both headers. They both slide up and in like.. well... you know..

Don't leave them loose, tighten them up.

Torque is 11 then 18 ft. lbs. Remember if you're using an extension you need to give it a little more torque. (Obvious to many, but not all).

[pdxrealtor]

11) Alright-- making progress! Now you're going to install the cats and y-pipe. This is all self explanatory once your to this point. There's no tricks or hang ups. Install it all, but don't tighten anything. You'll need to rotate your cats to position the o2 sensors in the right spot and get the rest of it to all line up. NO O2 EXTENDERS NEEDED WITH THIS KIT NOT EVEN CLOSE.

You' use the same clamp on the muffler, so don't remove it.

[pdxrealtor]

To be continued... I'm out of battery power.

[LoJac963]

awesome write up so far! The OBX's look awesome, they will definitely be a soon upgrade of mine before I get too many miles on those dang stock exhaust manis!

[Joe]

agreed, awesome post that sure will come in handy in next few weeks. Thanks!

[pdxrealtor]

12) Your cats and Y pipe are now all installed, but not tight. Start with your cats...rotate them so the O2s will screw in. On the driver side you'll see if you don't rotate the cats correctly your 02 sensor will be touching or very close to the front transfer case drive shaft. So plug that O2 sensor in, rotate your cat for the perfect position, then cinch up the cat to header connection. Obviously you want to tighten these three bolts evenly. Same thing on the other side. Make sure O2 sensor positioning is good to go and cinch the cat to header. You'll remove the O2 sensors after test fitting them, so you can get to the top bolt of the connection at the header/cat.

13) Now you'll have two sleeves mid Y pipe, and the connections at the muffler. Tighten both pipes at the muffler up, making sure your sleeve connections are nice and lined up first. This will allow for very easy final adjustments when you tighten the sleeves up.


You'll use the old bolts at the muffler end, so don't toss them when you take the old system out. FYI- I used a map gas torch to get the old connections loose at the muffler. Those were on good and rusted. The heat helped make it happen.

14) Now you have two more connection points mid way between the cats and muffler. One is on the cross over from driver to passenger side pipe, and the other is just after the passenger side cat. These connections are male/female so sliding the pipe in and out to the perfect line up is a piece of cake. Make your adjustments if needed, and tighten the sleeve bolts up. You might want to grab your tranny brush guard and make sure it fits, IE your exhaust is not hanging down to low. It shouldn't be an issue if you've lined everything up nicely.






These two pics show different angles of the O2 situation on the driver side





Y-pipe crossover sleeve. The sleeve on the passenger side is hidden by the crossmember

[pdxrealtor]

At this point everything is cinched up tight and you're all but done.

On the OBX system you have 3 holes you need to plug and some spark plug wire issues to deal with on the driver side. The system does not come with the plugs or any solution for the plug wires. Here's what I did.

15) The OBX system has 3 O2 bungs on each side, why?? I don't know, probably because it's made for more than one application . You'll want to use the bung in front of the cat, and the bung further down the pipes on BOTH SIDES. You're going to plug the bungs directly after the cats. The right size plug bolt is M18x1.5. My local ACE hardware had automotive plugs but short bolts should work the same way. If you do get the plugs they might come with a gasket. Don't use it. It's too hot and will disintegrate leaving your plugs loose. Use a liquid Teflon sealer, or high temp would work too.

16) Passenger side- You'll have an EGR hookup pipe coming off the header. You won't use it. The OBX kit does come with a gasket, which comes in handy. Now, there are probably several ways to do this. This is how I did it. I would have liked to cut the flange off and weld the hole but I didn't have access to a welder. When I was at ACE getting my O2 bung hole plugs I had the clerk cut me a 3/16" thick piece of steel. I think it is 2 3/4" long. Drilled some holes, painted it with high temp, threw the gasket on and bolted it up. You could also find a EGR block off from Summit or the like. Not sure if you'll find one or not. I was looking at KOK-90126BO at Summit, but wasn't sure it would fit.

[pdxrealtor]

Last and the most costly mistake I made- plug wires.

17) Hook up your plug wires. On the driver side the middle two wires will route in a way that they not only touch the header, they push against the header. Now, this may be a 'no sh*t sherlock' type of deal, but not for me. Since these wires were touching the pipes I wrapped them with the plastic heat shield. I have no idea what I was thinking, but I did it.. ok? It's done...lol. Learn from my mistake... or don't and treat yourself to a new set of spark plug wires.

18) Go to your auto parts store and get some heat tape. I got DEI brand. The heat tape was good. Didn't burn, mark up etc.... BUT it was letting heat through to the plug wire and that was making the plug boot at the coil pack to hot to touch. This is probably OK and you could call it done. I wanted to get a little more protection so I got some DEI wire/boot protectors. This keeps temps at the coil pack plug about 140*, 40* hotter than the other coil pack plugs. It also will prevent rubbing of the wire on the pipe. Another note... don't waste your money on header wrap just to wrap that one problem section. I did... and it turns out if you wrap just one section of the pipe it actually gets hotter. My header pipes are about 250* everywhere but where the header wrap is. There... it's 500*. It's coming off after I'm done with this wright up. The heat tape and boot/wire protector is plenty.



This is what you have to deal with....



This is what happens if you do it wrong



I double wrapped, 2 layers, of the below pictured heat shield tape



Installed with just heat tape



Pic of the finished product. The section of header wrap, as mentioned, is coming off.



Products I used

[pdxrealtor]

That's pretty much it. A side from the spark plug wire hiccup, not knowing the O2 bung hole plug size, and how I was going to plug the EGR port... it was a very smooth install.

Let me know if you have any questions on anything...

I can't wait to get a chip. Already there's a nice improvement but that chip should be the cherry on the top.

[tyler1bo]

Excellent write up. Would love to hear a sound clip!

[pdxrealtor]

I'll put one on youtube when I have a moment.

I'm very happy with the sound. Can't really tell any difference unless you get on it.

[H2Much]

Ahh man, I see what you are talking about now with the plug wires, that sucks! I will get a pic tomorrow on here of how mine ended up, but yah- that it nuts that they wrapped those things all around the plugs. Great post though, would you say the work was worth it for the sound and the extra boost?

[pdxrealtor]

Ya weird how they upped that one pipe the way they did. A pic would be great.

This was well worth the money and the work. Even better was the intune chip I just bought. Really makes the truck shift entirely different.



Should have done the chip 1st thing. Without the chip the headers just don't operate like they should. For that matter, without the chip the truck doesn't operat like it should.

[pdxrealtor]

Here's a dynatech header link w some pics.

Compare......

http://www.elcovaforums.com/forums/s...342#post548342

[pdxrealtor]

On another note...... The headers are nice, very nice, but without a chip youre missing out on what the headers offer.

I can't stress enough how important it is to get a chip and/or programmer after these mods.

I got the diablo sport inTune along with diablew tune (thx hellz for the referral) and with just the diablew 87 tune the truck was a new machine.

Currnently working with lew and I'm on the first tune. God damn.... TITS ... firm tits lol