2003 Toyota Tacoma code po304 po301

2003 TOYOTA TACOMA
140,000 MILES • 4 CYL • 2WD • AUTOMATIC
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BOOHAKER
  • MEMBER
  • 1 POST
check engine light on, (not flashing) code indicates engine cylinder one and three misfiring despite "tune up"... plugs, fuel filter, (no new plug wires) what's up with this code? safe to drive? advise on course of action...thanking you in advance...Boohaker
Feb 21, 2010 at 10:21 AM
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RASMATAZ
  • ✓Experienced Mechanic
  • 75,988 POSTS
Inspect and test all the following listed below:
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.
Feb 21, 2010 at 11:01 AM
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