Will removing the engine plastics be harmful to my Celica?
Most racers remove the engine plastics only because it get's in the way (for mods) or because they think their engine looks nicer without them.
There is a reason for it being there. If you remove it, you won't feel any difference in weight (or power), what you may notice over time is that your Hood
is beginning to change color.
The engine plastics are there to protect your factory stock Hood
from heat discoloration and to prevent violent change in engine block temperature during the winter (which can harm the engine block after the engine is turned off).
Your engine temperature is virtually the same while driving with or without the engine plastics in place. Put a heat sensor strip on top of your engine and see for yourself.
Generally it's wise to leave them in place because of the protection they provide to your Hood
(sorry about the dark photo, but at least you get the idea)