I have a 1993 F-150 with the 4.9 I6, when I fire it up, it has this awful screeching that sounds like 100 rats stuck in a single square-foot cardboard box. It's the smog pump that's making this noise, does anybody know what is wrong with it? How do I fix it before I go insane?

 

Bearing issue. You can either try to service it or replace it. Junkyard units probably aren't much better. Inactivity seems to ruin these. Some have eliminated theirs by installing an idler pulley or a different sized belt.. A search will yield your options.

 

Thanks, I really appreciate it. I think I'm just going to bypass it with a smaller belt.

 

Replacements are available
Not terribly expensive

https://www.google.com/search?client...UTF-8&oe=UTF-8