P0300 GMC Code - Engine Misfire Detected

Worn gears on distributer. replaced mine ran like a charm.

What does it mean if theirs a propane like odor coming from under t he hood

I have a 2007 gm Denali envoy...i have a propane like odor coming from the engine? What would be the cause?

Usually means that the fuel it's not burning, which could be caused by a faulty spark plug or ignition coil. P0300 means that there are more than one cylinder with the same problem. You should start by changing the spark plugs.

I have a GMC terrain 2.4 SLT, and for a week I have been presenting this code P0300 which was originally accompanied by the P0171, because everything seems to indicate that this fault is also interfering with the chevrolet equinox and my mention. And such models are not included in the GMC's bulletin on this fault # 03-06-04-030F.
According to Cadillac specialists in las vegas, this fault can be produced by the code P2135 GMC - Throttle / Pedal position Sensor /. So this can be taken into account since this fault is found according to my research in internet in almost all the vehicles of this year although they are not included in the factory bulletin # 11-06-04-007B. If the problem persists with such failures. Even if they do not write it down here. Because I will make a big noise through all the pages of internet and social networks. But just as I have Faith. Good thing there is Autocode my Pocket Consultant with his great app. Thank you

My friends gmc sea 1500 has codes p0300 and p1380 any ideas

Is the engine running rough? when was the last time you change the spark plugs? You could start by changing the spark plugs and use high octane gas for a couple of weeks.

I have a 98 GMC envoy. Getting this code now. Changed all my spark plugs and wires. Changed distributor cap and rotor. Changed oxygen sensors, maf/map sensor(was old). I can't think of any other reasons.

Rough ride while car is cold especially. When warm, runs better.

Have a Chevy truck 3/4 ton 2003 6.0 fuel injected with a 300 code truck starts and runs fine for about 10 miles starts missing and will finely shut down wait 5 to 10 min and can go another 10 miles but notice here lately that the milage is getting less replace the crank sensor and plug in and did not helpany suggestions are welcome

Any other codes? after the spark plugs, the most common problem for the P0300 and misfire is the Intake Manifold gasket.

I have a 2005 GMC Yukon which had original spark plugs and wires, but was running fine. We just changed all the spark plugs, but I forgot to use anti-seize on the plugs during installation. We are getting the P0300 code (x2, 1 send "PEND" and 1 said "MEM"). What are the odds this is caused by 1 of the following:

1) We were given the wrong spark plugs by AutoZone. We bought the Bosch Double Platinum 8104 pre-gapped plugs.
2) The lack of anti-seize is causing an issue.
3) I installed them too tightly and they are too far into the cylinder.

Any help would be great.

1. It's probably the most likely cause. I never seen the 2 or 3 triggering the P0300 code. What is the engine size of your Yukon? I can check if they give you the correct plugs.

Well, it turned out that #1 was sort of the cause. My son had apparently cracked the ceramic insulator installing the #2 cylinder's plug. Once that was replaced with a new plug, the error code went away. Thank you so much for your reply!

Thank you fore letting us know. I'm glad you find the problem.

Locked the motor up in 06 trail blazer. Replaced it with the same engine from an 02 envoy. Got it together n started it up, it ran beautifully. Drove it 3 blocks n it it backfired real loud n started missing bad. Got it back n put my scanner on it n had the p0300 code. Changed plugs, cam shaft aviator solinoid, crank sensor, put original intake back on with different gaskets. Still running like crap. I smelled of 2 of the plugs n they smelled like old gas. The other 4 were black as coal. Got hella exhaust coming out of tail pipe. It's a friend's truck n we don't know how long either truck sat. Coils are all firing. Also smelling the sulfar/rotten egg smell. Could it be the injectors? If not, what else could it be? Btw it's the 4.2 vortec engine....

Sounds like the there is no spark or some reason the gas is not burning. You could try getting all the gas out and add new.

I have a 2004 GMC Sierra that has a check engine light code p0300. The enginelight also flashes when I step on the gas pedal and it remains solid when I release the gas pedal. I replaced all spark plug and wires too. Not sure what to do. Or where to start.

Let me check if there is more information. What is the engine size of your Sierra?

I drive a 2004 GMC Sierra, I bought it in decent condition, but it has multiple sensor low voltage codes, probably caused by the alternator. It doesn't have any loss of power, or any symptoms listed, but I hook up my reader, and P0300 still exists. I've replaced all of the spark plugs, and tested the wires. Fuel pressure is good, fuel pump was replaced. Any idea of what's going on here?

Let me check if there is any more information. What is the engine size of your Sierra?

Have a 2007 Gmc Yukon Did a AFM DELETE
But I'm getting P0300 code engine is fully rebuilt new spark plugs new fuel injectors new wires new crank sensor new map sensor