Code P0300

[Mart86&04]

2004 6spd ;
Check engine light comes on setting a code P0300H. The car runs fine,
Idle is smooth no hesitation. Before the light came on I was in too high of a gear
causing the engine to bog down at around 1000 RPM's.
could that stumble cause this code?

 

[Huskerman]

Here are a couple of things to check.......my first idea is you have a bad plug wire or wires.....or a bad plug....



Need help fixing P0300 Misfire Code - Corvette Forum : DigitalCorvettes.com Corvette Forums

 

[Hib Halverson]

Here are a couple of things to check.......my first idea is you have a bad plug wire or wires.....or a bad plug....

Need help fixing P0300 Misfire Code - Corvette Forum : DigitalCorvettes.com Corvette Forums

That thread is typical of Digital Corvettes, not much info and a lot of BS.

DTC P0300 sets when the engine detects random misfire. The H means it's a history code which means the problem has happened recently but is not happening at the time you queried the PCM for codes.

Random misfire means that there's no pattern to the misfire being detected.

First thing I'd do is clear codes and road test. If the DTC sets again, do the easy stuff first.
Inspect your spark plugs. Replace as necessary.
Test the plug wires. The specs are in the Service Manual. Replace as necessary.

 

[Mart86&04]

P0300

This year has been crazy with this car. Back in October 2013 driving up to the finger lakes I started to get a code
P0101. Turns out the carbon fiber air duct had a crack. Replaced it with stock duct reset codes. It was a bad winter so the car was not used
much until May 2014, needed to have the car inspected, when the inspection station hooked up to the car they said there was no communication drive the car to reset. I went back 3 times now its the end of July and they are like hey this car is a manual trans not auto
so it passed. Then in August I got a bunch of no communication codes, replaced my 5 or 6 year old battery, that solved that problem.
Now I have the P0300, like I said idle is smooth and no driveability issues and fuel mileage is the same.
I did find the wiring harness rubbing through the tape on the bracket. Covering the wires to prevent possible short.

 

[gmjunkie]

DTC P0300 sets when the engine detects random misfire. The H means it's a history code which means the problem has happened recently but is not happening at the time you queried the PCM for codes.

Random misfire means that there's no pattern to the misfire being detected.

First thing I'd do is clear codes and road test. If the DTC sets again, do the easy stuff first.
Inspect your spark plugs. Replace as necessary.
Test the plug wires. The specs are in the Service Manual. Replace as necessary.

I agree!

I've had several C5 6 speed cars pop a P0300 when they have been lugged down so far that they buck,Keep it wound up and it'll probly never do it again!