Codes, P300, P301, P303, and P304 after driving several miles

208,000 MILES • 2.3L • 4 CYL • 2WD • AUTOMATIC
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XIST
  • MEMBER
  • 1 POST
For the fourth Tuesday in a row, my car had so many misfires I needed to reschedule my appointment. For the second time, I took it to my mechanic. The first time he told me to pull the plugs and check them. Yesterday they were closed at 4:00pm.
8/28 replaced spark plug tube seals.
9/04 replaced spark plugs (which were less than 14 months old).
9/11 replaced the distributor (leaked oil and the points were corroded) and cleaned the wires with electrical parts cleaner and Q-tips .
09/18 after driving about twenty miles the car misfired worse and worse. I cleaned the spark plugs and wires with soap and water, dried them with my compressor, and drove home without a problem.
How come the car drives fine for five miles, but then starts misfiring? It only misfires on the cylinders that had the oil leak!
Sep 18, 2019 at 3:36 AM
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SCGRANTURISMO
  • ✓Experienced Mechanic
  • 4,897 POSTS
Hello,

This sounds like a problem with your spark plug wires. You have replaced every other component of your ignition system except the spark plug wires. They should be changed every time you replace the spark plugs. Try this and get back to us with how everything turns out. We can go from there if needed.

Thanks,
Alex
2CarPros
Sep 18, 2019 at 7:35 AM
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