2000 Chevy Silverado random misfire


Electrical problem
2000 Chevy Silverado 6 cyl Two Wheel Drive Automatic 150000 miles

Can you tell me what would cause a random multi cyl misefire? I have already done the tune up with new plugs, wires, cap, and rotor button. It gets better after it warms up. The longer it runs the better it gets. Worse in the morning when you first start it. Thanks for the help. Akantmc3

Do you
have the same problem?
Sunday, September 21st, 2008 AT 9:41 AM

1 Reply



OBD2 P0300 may mean that one or more of the following has happened:

Faulty spark plugs or wires
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector(s)
Burned exhaust valve
Faulty catalytic converter(s)
Stuck/blocked EGR valve / passages
Faulty camshaft position sensor
Defective computer
Possible SolutionsIf there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.E. Spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.K.A. Coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.

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Sunday, September 21st, 2008 AT 9:46 AM

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