Check the belts. The most common cause of squealing is a worn or loose belt on the front of the engine.
AC Compressor
Check for a vacuum leak around the throtle body and intake manifold.
Though there are several possibilities, by far the most common reason for that is a loose or glazed belt in the engine compartment.
A worn or loose out of adjustment drive belt could be the cause.
no cause a 1994 may have a bigger engine
There ar pages and pages of things that can cause a check engine light. You need to have it checked for codes to know what to diagnose.
No. It is illegal, will cause a check engine light and running problems.No. It is illegal, will cause a check engine light and running problems.
-BeltA belt running one of the various components of your vehicle may be loose or in need of replacing/adjustment. Sometimes they simply get wet, and other times the tension pulley is out of adjustment. They slip on the pulley and cause the squealing until they regain traction. (Belts may run AC, water pump, alternators, engine fans etc)
The normal engine operating temperature for a 1987 Mustang GT is around 200 degrees Fahrenheit. Anything above 220 degrees Fahrenheit might cause the engine to overheat.
Running out of gas my certainly be a cause for the check engine light to come on. It could also be an assortment of other issues.
An engine usually has a higher idle speed when the ac is running. If the high speed idle does not operate then the ac will cause the engine to stall.