1991 Subaru Legacy

Engine Performance problem
1991 Subaru Legacy 4 cyl All Wheel Drive Automatic

engine hesitates at 800 to 1700 RPM's no codes are present. Also is firing on all 4 cylinders
Jeremy juntunen
May 21, 2010.

Check and test the following below

Oxygen sensor
Catalytic converter
Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)

Could also be an ignition system problem, such as plugs, coil, wires

May 21, 2010.