Been running very good, just got a synthetic oil change at the dealership, no sign of this coming...wondering why 2 did not code...
Your computer is getting confused by the crankshaft sensor signal. Do you also get the P0300 code? Check the tone ring for damage. If the ring is good, I would replace the sensor.
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SOURCE: Check engine light comes on. p0171 and p0351 codes found
From Lusty Kid:
I know the economy is bad, but change all of the plugs. Check your PCV Valve hose, 150 rottens them out allowing air to be sucked in, thus all kinds of codes.
Depending on mileage. Dismount the EGR valve and clean passages. If you are really good dismount the throtle position sensor body and clean out passages with Choke Cleaner., dismount where the EGR valves connects to the engine, clean out passages. Also check the hose thats behind this mounting to ensure is not clogged. If clogged clean it out. If not replace it. Is about 1.5 ft. long, connects to the PCV Valve Hose.
When is the last time you change your harness. Can't remember??? Replace it. Good Luck
SOURCE: Check engine light
A multi misfire may mean that one or more of the following has happened:
Faulty spark plug or wires, Faulty coil (pack), Faulty oxygen sensor(s), Faulty fuel injector(s), Stuck/blocked EGR valve / passages, Faulty camshaft position sensor, Defective computer.
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 wire, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the 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.
Good luck and hope this information helps, keep me posted, be glad to help you get the truck running 100% again. Not sure if your running a K&N air filter, and if you are there may be a flim of oil on the MAF sensor that is making you run lean. You may want to spray down the MAF sensor with a can of MAF cleaner.
SOURCE: Our 2005 Honda Odyssey had a check engine light / misfire
When a cylinder mis-fires there is a reason. The dealer should have told you that. Most likely you have a fouled out spark plug. Which means you need new spark plugs and maybe wires. All this would be covered in a standard tune up. Once the bad spark plug is replaced, the computer will quit registering a mis-fire. Please give good ratings, they meen a lot to us.... Thank you
SOURCE: 2007 aveo misfire faults
gm has a problem with this from way back. double check your spark plugs and if they are not ac delcos, change them. ive seen this time and time again swearing, myself, that there is no way that the plugs would cause this issue. it always comes up with random misfire and usually another 1 or 2 codes misfire codes. put in ac delco, no more codes. let me know
SOURCE: I have a 2003 trailblazer
P0300 - Random/Multiple Cylinder Misfire Detected
Basically this means that the the car's computer has detected that not all of the engine's cylinders are firing properly.
A P0300 diagnostic code indicates a random or multiple misfire. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. A P0302 code, for example, would tell you cylinder number two is misfiring. Unfortunately, a P0300 doesn't tell you specifically which cylinder(s) is/are mis-firing, nor why.
Symptoms may include:
* the engine may be harder to start
* the engine may stumble / stumble, and/or hesitate
* other symptoms may also be present
Causes: A code 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 Solutions:
* If 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.
About the your previous code (P0301), this code will trigger the check engine light as follows:
The misfire detection monitor, a software strategy built into the computer, is designed to detect an engine misfire. The computer can also normally identify the specific cylinder in which the misfire has occurred. A misfire is nothing more than a lack of combustion, which can be caused by poor fuel quality or metering, low compression, lack of spark or unmetered air entering the engine. There are other possible, less obvious causes as well, such as uncommanded Exhaust Gas Recirculatin (EGR), flow. When the misfire monitor detects a misfire, it will trigger the check engine light with the specific cylinder number as the last digit in the P030X code. For instance cylinder 1 misfire is P0301, cylinder 2 is P0302 etc.
Possible Causes:
Fuel injectors, related wiring, sensors and computer issues
Running out of gas, or poor fuel quality
Evaporative emissions system (EVAP) concerns: fuel vapors leaking into engine
Incorrect Fuel Pressure
EGR system concerns: leaking EGR valve or restricted ports.
Base engine concerns: low compression, valve train problems and timing issues
Ignition system concerns including, but not limited to:
Faulty spark plugs
Faulty coil or related wiring
Ignition module or related wiring issues
Ignition related sensor faults or wiring issues
Diagnostic Help:
Begin by checking for proper fuel and ignition system operation, and then follow up with the less likely causes listed above, such as EGR and EVAP system problems. New style coil on plug applications have a high failure rate, and can be concluded faulty by swapping to another cylinder and checking to see if the misfire moves to that cylinder. This is a quick check if a capable scan tool or oscilloscope is not available. Always make sure the basic maintenance is done first and that things such as the fuel filter, air filter, spark plugs and spark plug wires are in good working order, as these are all possible candidates for a problem. If necessary, check for wiring and component concerns. See our article "Automotive Circuit Testing 101", if you need more assistance with this. If concern is determined to be intermittent, check out our article on intermittent diagnosis and wiggle test connectors and wiring, attempting to duplicate concern. You may also use the "Get Help" link if you need specifications or have any other related questions. Remember to refer to an appropriate manual for specific instruction.
Keep us updated.
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http://technoanswers.blogspot.com/2012/01/bad-miss-at-idle.html
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http://schematicsdiagram.blogspot.com/2012/01/while-stop-engine-idles-like-cylinder.html
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http://schematicsdiagram.blogspot.com/2011/12/engine-misfire-codes-on-chevrolet.html
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http://schematicsdiagram.blogspot.com/2011/12/engine-misfire-codes-on-chevrolet.html
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http://schematicsdiagram.blogspot.com/2011/12/misfire-on-cylinder-4.html
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http://technoanswers.blogspot.in/2012/02/oil-on-spark-plugs-and-car-misfires.html
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This will help.
Thanks.
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