P0300 ULTIMATE GUIDE

▶︎In this video, you will learn what causes the P0300 code.

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[telefunkenyou]

1) I checked the plugs. They looked good. Cyl 1 plug gap was a little wide but I set it at .043 like the rest of them.
2) Checked the coils by unplugging and #2 was bad. Replaced.
P0300 cleared.
I got lucky.

[michellet_thatsme]

This is actually a pretty decent video. I'm surprised it doesn't have more viewer traffic.
Thank you for sharing this content. Great work!

[mannyfrommiami]

Who lost their mind after the first 30 different things that could cause the code?

[jaymontgomery]

This code could possibly be everything

[Sergeante]

Low oil level in those eco engines. Low oil can cause major damage obviously but didn't expect it to cause p0300 or even rough engine performance. I had to change the timing chain, guides and VVT solenoids in my nephew's Equinox

[danclay]

Everyone needs to remember that this list isn't the list of things that you replace until you bingo. This is list of the things you check and replace if you determine it is bad. You will have to search how to check several of these things. It is highly unlikely for you to have a several of these going on at once.

[thebluelunarmonkey]

Actually what is key to understanding misfire that this video misses, is that a misfire is detected when the RPM slightly dips on one cylinder's combustion stroke when compares to the RPM of other cylinders. This can be a misfire or fault of the crank position sensor in misreporting a misfire. When I say RPM slightly dips, example when idling at 800RPM on a 4 cylinder engine, there's 400 combustion strokes in a minute (4 cycle engine combustion/exhaust stroke every other revolution). The PCM would expect each combustion stroke exactly 0.15s apart. If a cylinder misfires, the RPM drops slightly and will take longer than 0.15s for the next combustion stroke since that cylinder didn't produce equal work as the other cylinders. With this understanding of misfire (slight dip in RPM/work performed at cylinder level) this opens your mind to all the things that could be the cause from an ignition wire that shorts to the block to a worn cam lobe that reduces intake mixture or exhaust gas.

[jasongadberry]

Had a p0300 code in my 02 Tahoe

Turned out to be bad reading from downstream O2 sensor
Which caused the truck to foul plugs

Pulled all the plugs
Hit them with. Wire brush to clean

Re installed existing plugs
Problem went away for right now

Planning on replacing
CAT converters
O2 sensors
Plugs
Wires
and coils

But after brushing off the plugs
It is running better than when I bought it🤷🏻‍♂️🤷🏻‍♂️🤷🏻‍♂️

[barbellsandwindmills]

2007 Volkswagen Rabbit 2.5L. Currently Suffering from P0300. I've replace (for the 2nd time in 6 months) All Coils & Plugs. 1st Fuel Injector, 1st Fuel Injector Pigtail Connector (Output Before: 0.7, After Installed: 2.4-2.7 (All the other are outputting 3.3 without Cranking it), PCV Valve Cover (Used), Top & Bottom O-Rings, Tested the Variable Timing Valve (Good), Cylinder Compression Test (Good), I AM Missing a bolt in the middle on the Air Intake Manifold. I'm going to attempt to replace it and or the entire manifold and possibly the Camshaft Position Sensor. After that, if it's something else, I have no choice but to sell my car.

[KenGaskins-nmgx]

Pretty thorough. I'd always start with the cheap, simple stuff that is easy to get to, unless you get another code to narrow it. Vacuum hoses, spark plugs, coils and air filter/clean throttle. When you check the plugs and you have some oil, you likely need a new valve cover gasket. Then the EGR valve and the PCV valve (under the car). Clean out the EGR valve and test it. You can also run tests on the fuel pressure, compression and the head gasket if you still have the code. You can check the MAF as well.
I'm sure I missed some stuff, but this how I would do it.

[tony]

Mine was the spark plugs three of them were literally missing the iridium on the end. It worked fine for a bit, then it was the wires. And after two weeks it was it started again and replaced the fuel pump.. it’s been 3 long years and it just started giving me a random misfire again. I’m thinking it’s the coil packs now. I have a 2010 block from a Silverado when I bought my 2000 Silverado, . I’m thinking it’s the oem accessory and components because the coil packs are round. The chassis should have like 300, 000 miles.

[Bigfeats]

Thanks for the vid. I watched a few vids before this and they were very lack luster as they did not cover as much stuff as your video.

[dennistirado]

BENT COIL CONNECTOR PIN: I had an annoying and hard to trouble shoot P0300 code on my 6 cylinder 2003 GMC Envoy XL. I had replaced the spark plugs and coils and the code and misfire would not go away. Why it did not trigger a P030x error, I don't know. Just passing this along as something simple for others to check. Have a nice day!

[rachelparent]

I have P0300 in a GM 3800 Series 3. Its running extremely rich and has burned out 2 catalytic converters. What should I look into for that is it likely fuel?

[braydenbrowning]

I had a bad fuel pressure regulator and a exaust leak

[GarrettGod]

My wifes 2011 mazda 3 itouring has a P0300 code right now. I went to change the spark plugs tonight and found oil in 3 spark plug wells. So currently i have the valve cover pulled and tomorrow i will replace the valve cover gaskets and hopefully it fixes the issue. To be continued.

[billsmith]

Here is another twist . A stuck open or intermittently sticking evap purge valve will cause the car to run horrible . On my 1987 Celebrity 2.8 L it would intermittently stick open . The vacuum would drop to 12 lbs. I finally blocked off all the hoses and drove it . The problem disappeared .

[FromClownedToCrowned]

A simple cracked air hose can cause a p0300 why are all the comments saying you need a new engine lol

[lambertt]

ECU ignition coil driver for cylinder 1 and 3 were not sending a 5 volt signal to ignition coil 1 and 3. Replaced ECU and solved issue.

[derekneedham]

I'm getting a code p300 like that welcome to my nightmare that is the hardest problem to diagnose I've learned a valuable lesson here Don't spend a lot of money on a car with as many miles as my car has that was stupid on my part I'm headstrong it's my worst character flaw