Multiple cylinder misfires, codes P301, P304, P306 and P300

Tiny
FELIPE CASTILLO
  • MEMBER
  • 2002 HONDA ACCORD
  • 6 CYL
  • AUTOMATIC
  • 190,000 MILES
Car was running fine. Turned it on and within 30 seconds the TCS light and check engine light came on and car started shaking, idling funny. Put on code sensor and came back with faulty P301, P304, P306, and P300 multiple cylinder misfires. No other faulty codes, nothing for the TCS, drove car home and two day later made sure gas cap was on tight and restarted and did another check and same codes came up. I read it is okay to drive with TCS light on, but can I continue to drive it with the cylinder misfires?
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Saturday, July 13th, 2019 AT 8:45 PM

3 Replies

Tiny
STEVE W.
  • EXPERT
Welcome to 2CarPros. It's not really good to drive with the misfires, especially if the CEL is flashing. The reason for this is that the misfires will cause unburned fuel to enter the catalytic converters and this can easily damage them to the point they have to be replaced.
Because this was a sudden thing I doubt it is spark plug failure as they seldom fail as a group. However if they have not been changed in a while it would be a good first thing to check. Next would be to check the power feed to the coils, look at the wiring harness that the coil wires go into and look for damage or rubbing. All of the coils are fed from one fuse but because the engine still runs the fuse is good. Another thing to try, if the CEL isn't flashing would be to clear the codes and see if they suddenly come back. It is very possible that they were caused by a cascade effect where one cylinder dropped out but it causes a "false code" on the cylinders around it in the firing order. If you get back the same cylinder codes ((the P0300 is because you have three cylinders (1, 4 and 6) reporting a misfire)) Then I would likely change the plugs and see if the codes are still present. If the scan tool you used can view live data it might also give a clue as to the problem, but only if it shows the misfire counts.
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Sunday, July 14th, 2019 AT 6:53 AM
Tiny
FELIPE CASTILLO
  • MEMBER
Thank you.
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Monday, July 15th, 2019 AT 9:35 AM
Tiny
KEN
  • ADMIN
STEVE W. Is one of our best! Please let us know what you find. We are interested to see what it is.
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Wednesday, July 17th, 2019 AT 1:11 PM

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