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Intake Manifold Removal 06 TB, 4.2 Engine

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45K views 6 replies 3 participants last post by  sfcmount 
#1 ·
I had P0171 error code, bank 1 running lean, or too much oxygen. Research indicated either unmetered air or lack of proper amount of fuel entering the system. I started with focusing on unmetered air. I changed the air filter, checked PCV lines and connections, cleaned throttle body, replaced MAF, but problem persisted. I thought fuel filter might be clogged, but came to find out 2006 TB does not have it. I used four-five cans of fuel injector over a period of a month problem still persisted. I replaced oxygen sensors hoping that they were throwing the code erroneously. Problem persisted. I decided to replace the fuel injectors. Soon found out that it was more involved than I could imagine. The problem is the fuel rail is underneath the intake manifold and it had to be removed.
Here is step by step instructions to remove the intake manifold. Allow 3-5 hours to accomplish this:
1) Start the engine, remove fuel pump relay (#41 on the fuse box) to take the fuel pressure out of the lines. The truck will stop running.
2) Disconnect battery. Put the fuel pump relay back on.
3) Remove air box and throttle body from the intake manifold.
4) Take serpentine belt off.
5) Remove the metal bracket on top of the alternator (three 15mm and one 10mm bolts, #1 through #4, in picture #1).
6) Remove the alternator bolts (three long 15mm bolts, #5 through #7, in picture #1). Start with the bolt at the bottom (#5). You may have to pry the metal part of the hose flush to the bolt a little bit to gain access.
7) Disconnect electric connections behind the alternator, and pry the alternator out completely. Some wiggling is necessary but it eventually comes out.
8) Disconnect three large wire connectors attached to the plate which is attached to the manifold (picture #2).
9) Disconnect the hose from the manifold that goes to the brake booster (#1 in picture #2).
10) Disconnect the top part of the hose in the middle of the manifold (#5 in picture #3) because there is one 10mm bold behind that hose (#2 in picture #3). You might want to replace that hose once the manifold is out. Mine cracked when I was prying it out. It did not have a clamp but I put one anyways.
11) Remove another metal bracket attached to the manifold which is on the alternator side. There is only one 10mm bolt holding it (#3 in picture #3). The bolt is underneath. You need to feel by your hand where the bracket ends to find that bolt. Unhook all the wires and lines attached to it and get it out of there. Once that bracket is removed, you should be able to reach all ten 10mm bolts holding the manifold (all circles in picture #3 except #3 which is bolt for the bracket and #4 which for plastic wire holder, I broke mine and put a zip tie instead).
12) You will need 3-4 inch extension to reach most bolts. The one closest to the firewall does not allow a straight extension (#6 in picture #3), but a small wrench works just fine. Don’t forget the bolt hiding behind the hose in the middle of the manifold that you unhooked. Bend the unhooked top part of the hose down to reach that bolt. All of the bolts will come loose but won’t completely come out, I guess to prevent them from falling down.
13) When all the bolts are out, the manifold should come off from the engine block. Pull it away from the engine block and push it down and back as much as possible to clear it off from the AC line in the front. You may have to pull the AC line out a little. With a little wiggling it can be taken out completely.
 
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