Sounds like the idle air controller is cycling. There are lots of conditions that
cause this but probably the easiest to check for is a vacuum leak. Open the
hood and listen for a sucking sound. It should lead you to a broken vacuum
line. Another possibility is a crack in the power brake booster diaphragm.
When you apply the brakes the crack opens wider leaning the engine way out.

Oh and if you have a check engine light stop by Autozone and they will read
the codes for you for free. Once you know what the codes are write me back.
Question:
1997 Ford Escort
Warning lights = Service engine soon.
Question: After driving for a short while and coming up to a stoplight the
car will act like its about to die, so i take my foot off the brake and slowly
move forwards and it stops. Its kind of like the car is breathing, the RPMs
go from 1.5 to .5 to 1.5 to .5.  Why is this happening?