2001 Subaru Outback Idles rough, poor acceleration, stalls at stop

Answer 1

The o2 sensor in this car is an air fuel ratio sensor or wideband o2 sensor. If it is bad, you car will stall, surge, chug and all sorts of weird things because the fuel is metered finely by the input from this sensor which has now been corrupted. If you ran the fuel level down to empty, you may have leaned out the exhaust gas to the point where the aging a/f sensor (o2 sensor) finally went and became useless (they are not as sturdy as traditional o2 sensors). You have a code for it which is fortunate for you (as a starting point) since they usually do not turn on the engine light when they misread the exhaust content (because at this point it still passes Fed standards). Just be sure it is the fornt sensor you have a code for and not the rear. This sensor can only be tested with an oscilloscope while driving or by a person who can interpret a graphical output and must respond to the throttle position (the ecu does not sample the data in real time). You must use a subaru part because aftermarket sensors will not be sensitive enough for the computer to pass them as functional (aftermarket sensors are calibrated to Fed standards and not international standards as Subaru sensors are).