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Here's a great DIY that will help you get to the rear (right) bank: Spark Plug / Ignition Coil Replacement
. Dealing with the two bolts on the rear of the intake collector is a PITA the first time. The tube seals are built into the valve covers. If you have an oil leak in the spark plug tube, replace the valve cover as well. RTV the corners of the gaskets as you will read in some of the links I have provided below. Although Nissan directs to replace the intake plenum gasket anytime you remove it, you really only need to do so if you have distorted it by removing the plenum, if you have a vacuum leak there, or if it has oil on it.
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