P1300

[P13OO]

The scan tool indicates Diagnostic Trouble Code (DTC) P1300 or some of PO3O1-PO3O6: Random misfire.


Description
Misfire detection is accomplished by monitoring the crankshaft speed with the crankshaft position sensor which is attached to the crankshaft.
If misfiring strong enough to damage the catalyst is detected, the MIL will blink during the time of its occurence, and misfire DTCs 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 misfire DTCs 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.

PO1O6: MAP sensor
P0171, P0172: Fuel metering
P0401, P1491, P1498: EGR system
PO5O5: Idle Control System
P1361, P1362: TDC sensor
P1381, P1382: CYP sensor
P1508: IAC valve

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
^ Distributor: malfunction
^ Ignition coil wire: open, leakage
^ Ignition control module: malfunction
^ MAP sensor: wrong characteristics, poor response
^ Valves: carbon deposit
^ Compression: low
^ IAC valve: malfunction
^ Fast idle thermo valve: malfunction
^ Fuel: does not meet Owner's Manual spec., lack of fuel




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

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