Check the image and let.me know what part is this?





It seems repaired in the past and i cant find a code for it. What does it do? How do i know if its failing?

20 years old and i have no idea what happened to it. There's a gray silicone filler thing in it.

Car is misfiring and ive been researching what it is.

 

Idle Air Control Valve.

 

That won't cause your misfire...in a car or truck.

 

Got a misfire? Time to pull some plugs and read them.

 

^this

 

I know you said you couldn't get a code for the IAC, but did you get any P03xx codes? A solid misfire or repeated will set a code showing which cylinder is misfiring. You said it was misfiring, so post whatever codes you have. It saves you time and money if you have codes to show the problem source.