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This article shows you how to swap your stock 4.7 manifold for a High Output manifold.
Parts Required
Tools Required
NOTE - Tools listed are what I used when doing this swap. May require other tools if you have the stock air-cleaner setup.
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NOTE: you may want to relocate your IAT (Intake Air Temp) sensor from the manifold to the air intake tube (if you have one). Since the manifold gets hot, moving it to the intake tube gives the PCM a more accurate reading. To block off the hole, there is a plug available, either on your new manifold, or find one at the wreckers. It's located over the #5 cylinder port on the manifold.
Gaskets were the easy part - They are O-rings, located at each port and at the TB mount. Pop 'em out, look 'em over, grease 'em with a little Vaseline, pop 'em back in! Mix n' match from the old and new manifolds, they are identical.
MAP sensor, located on the front of the manifold, comes out with a Torx bit.
Start by relieving the fuel pressure by pulling the fuel pump relay or fuse and cranking her over a few times. Then disconnect the battery and remove it (if tray needs cleaning, otherwise not needed).
Remove your air intake system (stock or aftermarket), and start disconnecting vacuum lines. They are hard to screw up, but if it helps, label the hoses.
Next come the electrical connections - TPS, MAP sensor, Idle Air Control, IAT sensor, coil packs - and then pull the coils. Tip - The nut that holds the coil to the manifold fits nicely in the boot of the coil so you don't lose 'em.
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Next, remove the throttle body. Just disconnect the throttle cable, cruise cable, then it's three screws and it's off.
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The heater hose that crosses over the manifold is actually easy to deal with. Just pop the ends off and set aside.
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Now comes the biggest PITA on the whole deal - The fuel system. I've heard that on some trucks, you can get away with not removing the injectors and rails. I was not so lucky. I disconnected the injector wiring at each hole, then removed the mounting bolts. Since I don't have the special tool required to remove the fuel line from the rail, I popped the rails off, and moved it around as I needed when I removed/installed the manifold. This is also a good time to check your injectors, and replace any o-rings as needed (4 for me). Use a little Vaseline on all o-rings before you reinstall the injectors (same on the coils, too).
With the fuel rails out of the way, and various hoses and lines moved as needed, unbolt the manifold. Use the reverse of the tightening sequence (Haynes/Chilton manuals have it). Remove the manifold. Enjoy getting the square peg (manifold) through the round hole (Fuel rails/hoses etc.) twice. The more you can open the hole up, the easier it will be.
![]()
Install was the reverse of the removal, changing cracked hoses as you go.
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When it's all together, fire her up, check for vacuum leaks.
Parts Required
- HO Manifold of your choice: 2002 -> good, 2003-2007 -> better, 2008-2011 -> best
- Vacuum caps (for unused vacuum ports on the manifold)
- Vaseline
- 5/8 heater hose
- 8mm vacuum hose
- Replacement electrical harness clips (fuel injectors, coils etc.) *DEALER ITEMS*
- Black electrical tape for any connections that look like they are loose.
Tools Required
NOTE - Tools listed are what I used when doing this swap. May require other tools if you have the stock air-cleaner setup.
- 8mm socket
- 10mm socket
- 10mm deep socket
- Small adjustable wrench
- Large pliers
- Needle nose pliers
- Torx set
- Small pry bar
----
NOTE: you may want to relocate your IAT (Intake Air Temp) sensor from the manifold to the air intake tube (if you have one). Since the manifold gets hot, moving it to the intake tube gives the PCM a more accurate reading. To block off the hole, there is a plug available, either on your new manifold, or find one at the wreckers. It's located over the #5 cylinder port on the manifold.
Gaskets were the easy part - They are O-rings, located at each port and at the TB mount. Pop 'em out, look 'em over, grease 'em with a little Vaseline, pop 'em back in! Mix n' match from the old and new manifolds, they are identical.
MAP sensor, located on the front of the manifold, comes out with a Torx bit.
Start by relieving the fuel pressure by pulling the fuel pump relay or fuse and cranking her over a few times. Then disconnect the battery and remove it (if tray needs cleaning, otherwise not needed).
Remove your air intake system (stock or aftermarket), and start disconnecting vacuum lines. They are hard to screw up, but if it helps, label the hoses.
Next come the electrical connections - TPS, MAP sensor, Idle Air Control, IAT sensor, coil packs - and then pull the coils. Tip - The nut that holds the coil to the manifold fits nicely in the boot of the coil so you don't lose 'em.
Next, remove the throttle body. Just disconnect the throttle cable, cruise cable, then it's three screws and it's off.
The heater hose that crosses over the manifold is actually easy to deal with. Just pop the ends off and set aside.
Now comes the biggest PITA on the whole deal - The fuel system. I've heard that on some trucks, you can get away with not removing the injectors and rails. I was not so lucky. I disconnected the injector wiring at each hole, then removed the mounting bolts. Since I don't have the special tool required to remove the fuel line from the rail, I popped the rails off, and moved it around as I needed when I removed/installed the manifold. This is also a good time to check your injectors, and replace any o-rings as needed (4 for me). Use a little Vaseline on all o-rings before you reinstall the injectors (same on the coils, too).
With the fuel rails out of the way, and various hoses and lines moved as needed, unbolt the manifold. Use the reverse of the tightening sequence (Haynes/Chilton manuals have it). Remove the manifold. Enjoy getting the square peg (manifold) through the round hole (Fuel rails/hoses etc.) twice. The more you can open the hole up, the easier it will be.
Install was the reverse of the removal, changing cracked hoses as you go.
When it's all together, fire her up, check for vacuum leaks.
