Hello, I currently have the intake plenum, cooling fans, and intake/air filter housing off while I  replaced the engine harness. While doing that I have done a Big 3 upgrade and am replacing all motor and tranny mounts. Replaced coils and spark plugs since the intake is off. Also a coolant flush and fill will be done.


I am considering disassembling the plenum to clean it out and replace the 3 gaskets, but dont know if it's worth the trouble or theres much benefit...


Does anyone have any suggestions on what other components would be a good idea to replace while I have easier access? Also the car has not been started in over a year so I'm also inquiring about any other components that need to be refurbished or replaced due to car being off the road for this long?


Thanks in advance.

If the 3.5 engine in your Altima is anything like the 3.5 in my Pathfinder, then the EGR valve is impossible to change without removing the plenum.
If you take it off, take the opportunity to replace it.