P1300

[P1300] or [P1301] through [P1306] or [P1201] through [P1204] The scan tool indicates Diagnostic Trouble Code (DTC) P1300 or some of P1301 - P1306: Random misfire.

Description
Misfire detection is accomplished by monitoring the voltage of the spark plug with the spark plug voltage sensor which is built in to the ignition coil.
If misfiring strong enough to damage the catalyst is detected, the MIL will blink during the time of its occurrence, and DTC P1300, some of DTCs P1201 through P1206 or some of DTCs P1301 through P1306 will be stored. Then, after misfire has ceased, the MIL will come on.
If misfiring that increases emissions is detected during two consecutive driving cycles, the MIL will come on, and DTC P1300, some of DTCs P1201 through P1206 or some of DTCs P1301 through P1306 will be stored.

NOTE: If some of the DTCs listed below are stored at the same time as a misfire DTC, troubleshoot those DTCs first, then troubleshoot the misfire DTC.

P1128-9: MAP sensor
P0171, P0172, P0174, P0175: Fuel metering
P0401, P1491, P1498: EGR system
P0335, P0336, P1336, P1337, P1381, P1382, P1386, P1387: CKP/CYP sensor
P1259, P1279: VTEC System

Possible Cause
- Fuel pump insufficient fuel pressure, amount of flow
- Fuel line clogging, blockage, leakage
- Fuel filter clogging
- Fuel pressure regulator stuck open
- EGR system malfunction
- Ignition coil wire open, leakage
- Ignition control module malfunction
- Carbon deposits on valves
- Compression low
- Fuel does not meet Owner's Manual specification., lack of fuel
- VTEC system malfunction




Troubleshooting
By test-driving, determine the conditions during which misfire occurs. Depending on these conditions, test in the order described in the table below.

NOTE: If misfire doesn't recur, some possible causes are fuel that doesn't meet owner's manual specification, lack of fuel, carbon deposits on spark plug, etc.