4th gear pull and got Code P0300 (ENGINE MISSFIRE) for the first time.
#1
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So I was cruising on a HW at about 230am and decided to drop down to 4th gear and punch it since it was empty, it was a long straight strech and hadnt felt the power of the car in a little while.
To my surprise mid way thru the pull the car stuttered/bucked and felt an imediate loss in power. Mean while I started seeing the code P0300 (ENGINE MISSFIRE) on the DIC and also my Check Engine Light started flashing. I imediately let off and cruised. This lasted about 15-30 sec. And its the only time the car has ever behaved like that.
The car seemed to run fine after that without any issues.
Any input anyone as to what could have beent the cause of this happening like that?
To my surprise mid way thru the pull the car stuttered/bucked and felt an imediate loss in power. Mean while I started seeing the code P0300 (ENGINE MISSFIRE) on the DIC and also my Check Engine Light started flashing. I imediately let off and cruised. This lasted about 15-30 sec. And its the only time the car has ever behaved like that.
The car seemed to run fine after that without any issues.
Any input anyone as to what could have beent the cause of this happening like that?
#3
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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
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.
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
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.
#4
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My o2's are fried right now so i am throwing the same exact code along with 13 others since i did my long tube header swap. Does your car have longtubes and no cats?
I would start by checking the plugs and wires...make sure the plugs arn't bad. If you have longtube headers one of your wires might of touched and burned through the jacket. I think your coils should be alright because more thank likely when they go bad its one at first and usually its one cylinder at at time that starts misfiring. After that check your o2 sensors. Make sure the harness isnt damaged and check the sensor for carbon build up. I would do a full tune up just to be safe. Last check injectors. You might be having low fuel pressure problems. If you havent changed the fuel filter in a while change it out since they are pretty cheap. If everything seems good after checking the above check for vacumm leaks.
I would start by checking the plugs and wires...make sure the plugs arn't bad. If you have longtube headers one of your wires might of touched and burned through the jacket. I think your coils should be alright because more thank likely when they go bad its one at first and usually its one cylinder at at time that starts misfiring. After that check your o2 sensors. Make sure the harness isnt damaged and check the sensor for carbon build up. I would do a full tune up just to be safe. Last check injectors. You might be having low fuel pressure problems. If you havent changed the fuel filter in a while change it out since they are pretty cheap. If everything seems good after checking the above check for vacumm leaks.
Last edited by camaro981289; 03-06-2011 at 06:46 PM.
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Thanks for all the info,
See the thing is that after that episode it hasnt happened again. The car runs fine.
It only lasted like 15 sec so Im just trying to figure out why it could have acted like that without any long term symtoms or ill effects.
See the thing is that after that episode it hasnt happened again. The car runs fine.
It only lasted like 15 sec so Im just trying to figure out why it could have acted like that without any long term symtoms or ill effects.
#7
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LS motors have their moments sometimes lol, i would do a tune up if you havent in a while if i were you, just to make sure it runs good and to prepare it for the summer since you will probably be doing alot of driving. Thats a nice C5Z BTW. Good luck man