QuestionCan you be very specific as to the removal of the intake plenum to access the back 3 plugs?
AnswerSure. My best recollection is below. I also recommend you review the procedure at www.hmaservice.com. The site requires Internet Explorer, and you'll need to register for a free account. Gather as much information as you can from both my procedure and the one in the shop manual, and approach the job being careful to look for things that may have been missed.
1. Loosen the clamp attaching the air intake bellows to the intake manifold.
2. Unplug the air flow sensor and remove the top of the air cleaner, the air flow sensor, and the bellows as an assembly.
3. Unplug the throttle position sensor, the idle actuator, and the air temperature sensor.
4. Unplug the rear bank injector wiring and remove the connector from the holding tab.
5. Disconnect the PCV hose from the PCV valve.
6. Disconnect the fuel pressure regulator vacuum hose from the manifold.
7. Remove the two 10mm bolts holding the throttle cable bracket to the plenum.
8. Remove the 10mm bolt attaching the ground wire to the plenum.
9. Remove the throttle cables from the throttle linkage.
10. Remove the three 12mm bolts attaching the rear of the plenum to its support brackets.
11. Remove the five 12mm bolts and two 12mm nuts attaching the plenum to the lower manifold.
12. Lift the plenum off the manifold and rotate the passenger side upward so as to stand the plenum up on its side.
13. Cover the exposed intake holes to prevent anything from dropping into the combustion chamber.
Once you have the plenum out of the way, replacing the plugs is a simple task. Due to the effort involved, I'd recommend replacing the spark plug wires at the same time as the plugs.
