1998 Subaru Forester slight miss

1998 SUBARU FORESTER
17,000 MILES • 4 CYL • AWD • MANUAL
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DECKER109
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  • 1 POST
This was all done by a mechanic. Had a code to replace cats,did that. Was told I needed a tune up,did that,New plugs,wires fuel filter air filter.Still my engine was missing.We have now replaced the mass air sensor.I am getting no code and I still have a slight miss.Why?
Jul 4, 2010 at 12:34 PM
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RASMATAZ
  • ✓ASE Certified Mechanic
  • 75,992 POSTS
  • ASE Certified Mechanic
Engine running rough or misfiring can be cause by the following:

1.Defective spark plug
2.Inadequate spark/coil,defective spark plug wire.
3.Lack of compression
4.False air leakage.
5.Faulty fuel injectors.
6.Insufficient fuel pressure.
7.Contaminated fuel.
8.EGR valve that is leaking.
9.Oxygen sensors.
10.Throttle position sensor.
11.Idle air control valve.
Jul 4, 2010 at 3:50 PM
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