When I removed the plugs there was oil in the tubes on my '97 avenger 2.5L. Is this normal?

 

You need to replace the plug well seals.

 

No it's not normal ... You need a valve cover gasket set (it comes with plug well seals )
You'll also need some high temp silicone RTV to do the install

 

Do I use silicone on both sides of the valve cover gasket? Should silicone be used on the new intake plenum gasket? The old gasket feels like a rubber material and the new gasket seems to be metal. Anyone know if this metal gasket requires a sealant?

I removed the intake plenum and found a lot of oil in the rear tubes and inside of the wire plug socket . This may be stupid question, but is it possible that all this oil on the wires and plugs caused the engine to stall?

 

yall dont use no sealers on this stuff. never use no sealers on intake plenum and forsure not on the valvecover except in the the corners where it goes from flat to arund the cam caps. and jsut a little dab. i seen allot of guys gob the snot out sealers and then it gets into to the moter plugs the pickup screen and smokes the barings.

 

You HAVE to use silicone on the plug well seals to attach them to the valve cover , I apply a thin film and attach the plug seals and let them set up ... As well as the valve cover gasket ... this prevents moving when you flip up / over the valve cover
You can also use the gasket adhesives to hold it in as well

no sealant on the intake gasket ...

Oil can cause misses stalling as it grounds out the plugs