Manifold Air Pressure or Barometric Pressure sensor is out of range
The 1989 Ford Mustang 302 cubic inch engine has an oil capacity of 4 quarts. The engine oil should be changed every 7000 miles or every three months.
According to fordparts.com the 1989 Ford Mustang GT has ( 1 ) oxygen sensor
220 horsepower for the high output 5.0 ( 302 cubic inch ) in a 1989 Ford Mustang ( the 8th " character " of the VIN is an " E " )
220 horsepower for the high output 302 in a 1988 Ford Mustang
I believe that is ( 220 horsepower ) for the High Output 5.0 liter / 302 cubic inch V8 in a 1989 Ford Mustang GT
302
The stock engine, a 5.0 or in reality a 4.9 liter had approx 225 horsepower.
That is a 1989 Ford Mustang : ( With the High Output version of the 302 cubic inch / 5.0 liter V8 engine )
My 1991 Ford Mustang LX 5.0 L ( 302 ) was rated at 225 horsepower
200hp
( .054 inch ) according to fordparts.com for the 5.0 liter / 302 cubic inch V8 engine in a 1992 Ford Mustang
From the factory ( 220 horsepower ) for the High Output 5.0 liter / 302 cubic inch V8 in a 1988 Ford Mustang GT