How To: Fix error code P0300 for random misfires on your car

Fix error code P0300 for random misfires on your car

Error code P0300 is one of the most infamous in auto maintenance, indicating random misfires in the engine. This can mean several different things, and in this video mechanic Scotty Kilmer will teach you how to figure out where the problem is and fix it.

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Thanks for the great info!

One thing you missed. The P0300 error can be caused by a bad MAF or Mass Air Flow Sensor. I had a problem with P0171 and P0174 errors and cleaned the MAF sensor. I reset my codes and it ran fine for a couple of days, then I started getting P0300 errors and other related error codes, and performance sucked. I talked with a friend who owns a repair shop, and he suggested the MAF had failed. I changed it, and now it runs better than it has in years.

Hi need help on figuring out what can be the misfire on my 2005 dodge neone I already changed out the spark plugs spark plug wires the air filter and fix a vacuum leak what els can it be any answers

It could be a bad coul. Or bad o2 sensor. What kind of codes are u getting. If not getting a p0050 or p0155 it's not o2 sensor. Another cause could be a bad ignition control module. But start by getting your coil checked first.

I also have an error code p0300 on my 20p5 dodge neon, its the only code. What worked?

Thanks for the video! Helped me figure out my car has an intake manifold gasket leak. Which apparently is common with the S series Saturns. Going to be my first time replacing one but worth it!

I own a 2002 Nissan Pathfinder and the other day it started to take a few seconds to turn over on hot starts and once in a while on cold starts. Another symptom I was experiencing was a rough idling, but as soon as I got to cruising speed it felt ok. The check engine light came on, I checked the codes got : p0300, p0158, and p0138. It didn't single out a particular cylinder or sound and feel like I had a dead cylinder so I did a check for vacuum leaks nothing. I cleaned my throttle body and my MAF and sprayed starter fluid all over the engine and vacuum lines nothing. Next I checked fuel I changed my fuel filter as I was trying to test my fuel pressure I came across a video that mentioned a Fuel Injector Pressure Damper the check was simple remove a vacuum hose check for fuel which I did have. For $80 I changed it out and it's back to its old self good as new. Just thought I'd share if anyone is having similar issues.

I have a 2011 Denali but after I went over some railroad tracks kind of roughMy engine light started blinkingAnd a little car with the zigzags came on after putting a small hand computer on it it showing a misfire on cylinder for a friend of mine changed out the engine coil And it did not help then he changed out the spark plug in the wire and just number four and it is still running rough showing the same lights tomorrow he is going to change all my spark plugs I hope that helps but if not what else could it be thank you so much for your help

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