Spark plug change?

Hello, I am Danny.

Yes, you do have to remove the intake manifold to gain access to the rear three spark plugs. It will take you roughly three hours to complete as the book calls for 2.2 hours. The gasket you need to replace is simply called the intake manifold gasket. The intake manifold itself is held on by nine bolts however, a bunch of accessories will need to be removed. If you feel confident in performing this I can attach step-by-step pictures if you like. Hope this helps and thanks for using 2CarPros.
Danny-

Hi and thanks for using 2CarPros. Com.

Here are the directions for removing the intake manifold to access the plugs in the rear. All attached pictures correlate with these directions.

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REPAIR PROCEDURES
Removal and Installation

1. Disconnect the battery negative terminal.
2. Remove the engine cover (A).
3. Remove the air duct (B).
4. Remove the air cleaner assembly.
(1)Disconnect the breather hose (A) and the BARO sensor connector (B).
(2)Disconnect the air intake hose and then remove the air cleaner assembly (C).

Tightening torque
Hose clamp bolt:
2.9 - 4.9N.M (0.3 - 0.5kgf.M, 2.2 - 3.6lb-ft)
Air cleaner assembly bolts:
7.8 - 9.8N.M (0.8 - 1.0kgf.M, 5.8 - 7.2lb-ft)
5. Remove the under cover.
6. Loosen the drain plug (A), and drain the coolant. Remove the radiator cap to speed draining.
7. Disconnect the wiring connectors, harness clamps and hoses from the engine.
(1)RH front, rear oxygen sensor connector (A).
(2)VIS connector (B).
(3)RH exhaust camshaft OCV connector (C).
(4)RH ignition coil connector (D).
(5)RH injector connector (E).
(6)VCM connector (F).
(7)Power steering switch connector (G).
(8)LH exhaust camshaft OCV connector (A).
(9)LH/RH intake camshaft OCV connector (B).
(10)Oil pressure switch connector (C).
(11)Knock sensor connector (D).
(12)VPS connector (E).
(13)Condenser connector (F).
(14)Ground (G).
(15)Disconnect LH front oxygen sensor connector (A).
(16)Disconnect alternator connector (A).
(17)LH ignition coil connectors (A).
(18)LH injector connectors (B).
(19)VIS connector (C).
(20)LH intake CMPS connector (D).
(21)MAP sensor connector (A).
(22)PCSV connector (B).
(23)RH intake CMPS connector (A)
(24)Knock sensor connector (B)
(25)OTS connector (C)
(26)ETC connector (D)
(27)RH exhaust CMPS connector (E)
8. Disconnect the PCSV hose (A), fuel hose (B) and throttle body coolant hoses (C).
9. Remove the throttle body mounting bolt (D).

Tightening torque:
18.6 - 23.5N.M (1.9 - 2.4kgf.M, 13.7 - 17.4lb-ft)
10. Disconnect the PCV hose (A) and remove the surge tank stay (B).

Tightening torque :
27.5 - 31.4N.M (2.8 - 3.2kgf.M, 20.3 - 23.1lb-ft)
11. Remove the surge tank (A).

Tightening torque:
9.8 - 11.8N.M (1.0 - 1.2kgf.M, 7.2 - 8.7lb-ft)
12. Remove the delivery pipe & injector assembly (A).
13. Remove the intake the manifold (A).
NOTE:
Cover the inlet of cylinder head with a clean cloth or vinyl cover to prevent foreign materials from entering the engine.

14. Installation is reverse order of removal.
Tighten the intake manifold bolts and nuts, in several passes as below.

Tightening torque
Step 1: 3.9 - 5.9N.M (0.4 - 0.6kgf.M, 2.9 - 4.3lb-ft)
Step 2:Nut- 18.62 - 23.52N.M (1.9 - 2.4kgf.M, 13.74 - 17.36lb-ft)
Bolt -26.5 - 31.4N.M (2.7 - 3.2kgf.M, 19.5 - 23.1lb-ft)
Step 3: Repeat 2nd step twice or more.

A - h : 1st step order
1 - 8 : 2nd step order
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I hope this helps. Let us know if you have other questions.

Take care,
Joe

You are welcome!
Let us know how it goes. Thanks again for using 2CarPros.
Danny-

OEM are NGK 9723 with a.044 gap. I would replace them while it is off. At 120,000 it has seen a lot of heat cycles. Please let us know if you need anything else to get the problem fixed.

When first starting a car (key in start position)a full 12 volts goes to the ignition system to help start a cold engine. When you release the key to the run position, the voltage drops so the system last longer. Have them check to see if there is a drop in voltage.

If it doesn't lower the voltage.

This does seem excessive for what must have took around 2 hours labor at most, plus the cost of parts ??

This is a strange coincidence but we have o way to know what went wrong with your engine. It needs to be looked into further but I don't know if these are the people to do that. As far as the bill goes, you stated " I had them change the spark plugs and wires". Does that mean you made the decision that it needed plugs and wires or did they diagnose that as the problem. That would determine who should eat that money.

I guess you need to get a second opinion and find out exactly what the problem is and whether they were the cause in any way which I doubt. If they didn't cause the problem, the most they are guilty of is misdiagnosis and even that doesn't seem to be the case after the way you explained the conversation. Just because they weren't aware of internal damage doesn't make them responsible for the problem unless they somehow caused it.