2000 Jeep Cherokee

Engine Performance problem
2000 Jeep Cherokee 6 cyl Four Wheel Drive Automatic 190000 miles

OVD2 computer scanned my vehicle and the outcome was misfire on cylinder's 1 and 3. What does that mean?
March 24, 2010.

Engine running rough or misfiring can be cause by the following-inspect and test all the following below: 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.

Mar 24, 2010.