Engine seems to stumble mainly when warmed up

2001 SUBARU OUTBACK
105,000 MILES
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SHEVA
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I have a 2001 Subaru Outback 2.5 and when the a/c engages the engine stumbles and almost cuts off. It feels like it is losing all power for a second or so then idle fluctuates and smooths out. Any ideas?
Oct 24, 2011 at 2:08 PM
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RASMATAZ
  • ✓ASE Certified Mechanic
  • 75,992 POSTS
  • ASE Certified Mechanic
https://www.2carpros.com/articles/engine-hesitates

Could be caused by one of the following below

Oxygen sensor.

Catalytic converter.

Fuel injectors dirty/sticking.

Mass airflow sensor/Airflow meter.

Throttle position sensor.

Crankshaft position sensor

Knock sensor

Manifold absolute pressure sensor.

EGR Valve

Fuel pressure regulator leaking or defective fuel pump.

Fuel contamination.

Foul/defective spark plugs.

Open spark plug wires.

Ignition coil/Coil packs defective.

Incorrect ignition timing.

Cap and rotor.




Note:If it doesn't apply disregard it and keep testing.
Oct 26, 2011 at 4:08 AM
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