I have a multiple cylinder engine mis Fire code. It happens every morning after 4-7 miles. Car goes into limp mode, I pull over shut off and restart and do not have an issue the rest of the day.
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 What does this mean? What does this mean? 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". There is a factory service bulletin for the following GMC models: 2000-2008 GMC Sonoma 2000-2008 GMC Sierra 2000-2008 GMC Yukon 2000-2008 GMC Yukon XL 2001-2008 GMC Denali 2001-2008 GMC Denali XL 2001-2008 GMC Savana 2002-2008 GMC Envoy 2002-2008 GMC Safari 2002-2008 GMC Jimmy 2000-2008 GMC Factory Service Bulletin OBDII Code P0300
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