P0300 code
Thread Starter
Intermediate
Joined: Jun 2012
Posts: 44
Likes: 0
From: Gardner Kansas
P0300 code
At the in-laws tonight for a little party. When it was time to leave, I started the car and it was running pretty rough. Drove a little further and it seemed to get worse. Then the check engine light came on and started flashing. I pulled into a parking lot and checked the codes. I got a P0300 code. Luckily I was just down the road from from my uncles shop, so I was going to just drop it off and have him look at it in the morning. I then started it and it ran just fine. I drove it home, about 25 miles, with no trouble. Is this something I should be worried about?
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
P-0300 is a RANDOM MISFIRE Normally, the problem is caused by defective spark-plug wires or a damaged / cracked plug insulator. If it was an out of the clear blue issue, it probably a plug wire issue.
One cylinder misfiring can feel like the engine is ready to self destruct!
Check to see if the wires are fully seated on the coil towers and on each plug. Was it raining or damp out??
If you find that you need wires, I recommend the GM Performance Red Wires. They are only 60ish dollars and fit and work flawlessly!
Contact www.gmpartshouse.com and talk to Gene or Patrick
One cylinder misfiring can feel like the engine is ready to self destruct!
Check to see if the wires are fully seated on the coil towers and on each plug. Was it raining or damp out??
If you find that you need wires, I recommend the GM Performance Red Wires. They are only 60ish dollars and fit and work flawlessly!
Contact www.gmpartshouse.com and talk to Gene or Patrick
Drifting
Joined: Nov 2005
Posts: 1,320
Likes: 242
From: NW Chicago
St. Jude Donor '12-'13-'14-'15
That's the code that I had when I had a broken valve spring. Rough idle and sputter. Worth a look. I started with wires and plugs,all the same, pulled pass. valve cover and problem found.
Last edited by punz; Jul 21, 2013 at 12:33 AM.
Drifting
Joined: Feb 2008
Posts: 1,596
Likes: 67
From: Bahama North Carolina
At the in-laws tonight for a little party. When it was time to leave, I started the car and it was running pretty rough. Drove a little further and it seemed to get worse. Then the check engine light came on and started flashing. I pulled into a parking lot and checked the codes. I got a P0300 code. Luckily I was just down the road from from my uncles shop, so I was going to just drop it off and have him look at it in the morning. I then started it and it ran just fine. I drove it home, about 25 miles, with no trouble. Is this something I should be worried about?
Thread Starter
Intermediate
Joined: Jun 2012
Posts: 44
Likes: 0
From: Gardner Kansas
P-0300 is a RANDOM MISFIRE Normally, the problem is caused by defective spark-plug wires or a damaged / cracked plug insulator. If it was an out of the clear blue issue, it probably a plug wire issue.
One cylinder misfiring can feel like the engine is ready to self destruct!
Check to see if the wires are fully seated on the coil towers and on each plug. Was it raining or damp out??
If you find that you need wires, I recommend the GM Performance Red Wires. They are only 60ish dollars and fit and work flawlessly!
Contact www.gmpartshouse.com and talk to Gene or Patrick
One cylinder misfiring can feel like the engine is ready to self destruct!
Check to see if the wires are fully seated on the coil towers and on each plug. Was it raining or damp out??
If you find that you need wires, I recommend the GM Performance Red Wires. They are only 60ish dollars and fit and work flawlessly!
Contact www.gmpartshouse.com and talk to Gene or Patrick
Race Director
Joined: Feb 2013
Posts: 19,864
Likes: 146
From: South East TN
I recently had a similiar problem. I used an ohm meter and read the spark plug wires out. I had no idea what they should read but knew that if I had a big variation in readings from one wire to the next that would indicate a problem. All of my wires read between 27-30 ohms except one which read 6000 ohms. If I placed the tips of the meter into the core of the wire I got 27 ohms so it was a connection problem between the wire and the connector that went into the coil. Replaced the wires but read the new ones before installing to make sure they were good, all were 27-30 ohms again. Now I have 7 used spares just incase, threw the one bad one away.
Drifting
Joined: Dec 2011
Posts: 1,706
Likes: 44
Just had that code and the car ran horribly.
I removed all of the plugs and wires and checked for resistance (cleaned the plugs while I was in there anyway, and found that the silver housing around the plug was keeping two of my msd wires from seating properly.
I removed the 2 shields and the problem instantly went away.
As a matter of fact, the car had a mysterious miss at idle that went away also. Thought it was the throttle body so I removed that and cleaned it with throttle body cleaner, but that wasn't the problem, although the pedal response was incredible after I cleaned it!!!!!
I removed all of the plugs and wires and checked for resistance (cleaned the plugs while I was in there anyway, and found that the silver housing around the plug was keeping two of my msd wires from seating properly.
I removed the 2 shields and the problem instantly went away.
As a matter of fact, the car had a mysterious miss at idle that went away also. Thought it was the throttle body so I removed that and cleaned it with throttle body cleaner, but that wasn't the problem, although the pedal response was incredible after I cleaned it!!!!!
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