P0300 LEXUS Random Cylinder Misfire Condition

Possible causes
– Faulty spark plug (s)
– Faulty ignition coil (s)
– Clogged or faulty fuel injector (s)
– Intake air leak
– Fuel injectors harness is open or shorted
– Fuel Injectors circuit poor electrical connection
– Ignition coils harness is open or shorted
– Ignition coils circuit poor electrical connection
– Insufficient cylinders compression
– Incorrect fuel pressure
Tech notes
The P0300 code means that a cylinder(s) is misfiring or is randomly misfiring. Start by checking for intake leaks, intake gaskets are common caused of multi-cylinder misfiring. If no leak are found the next step is to replace the spark plugs. If the problem persist more tests needs to be done to diagnose problem, see “Possible Causes”
When is the code detected?
The control module monitors the crankshaft speed and has detected a misfire condition
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
– Lack/loss of power
– Hard start
– Engine hesitation
P0300 LEXUS Description
When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, the Engine Control Module (ECM) can determine that a misfire is occurring.
LEXUS Technical Service Bulletins for P0300 code
2006 LEXUS GS300 ENGINE AND ENGINE COOLING:ENGINE
2006 LEXUS IS250 ENGINE AND ENGINE COOLING:ENGINE
2002 LEXUS IS 300 UNKNOWN OR OTHER
2002 LEXUS GS300 UNKNOWN OR OTHER
2002 LEXUS IS 300 UNKNOWN OR OTHER
2002 LEXUS GS300 UNKNOWN OR OTHER
2001 LEXUS LS430 ENGINE AND ENGINE COOLING:ENGINE:GASOLINE
2001 LEXUS GS430 ENGINE AND ENGINE COOLING:ENGINE:GASOLINE