Check Engine P300, P302, P303

[macuser27]

Did a track day last week and the check engine light came on during the third session.

Car starts up and idles fine, drives fine, feels and sounds normal. Drove it home from the track with no issues. Pulled codes P300, P302 and P303.

I drove it today, around 80 miles with no issues. Check engine light did not go away. Codes are the same P300, P302 and P303.

Car is a 2013 with 71,xxx miles on the chassis and 11,xxx miles on replacement engine.

What are the next steps? Replace coil packs in cylinder 2 and 3?

[p1l0t]

Ummm P0300?

Sent from my SM-G975U using Tapatalk

[soundman98]

You just read the codes, but didn't erase them?

Codes are stored in the computer until a certain amount of drive cycles are completed. I don't know the number, but it's a lot, so even driving the car every day for 2 hours for a week isn't going to clear the codes by itself.

So all the codes deal with misfires.

First step would be to erase the codes, and see if they come back.

Second step would be to run a different tank of gas through the car.

How full was the gas tank on the last session?

Don't be throwing parts at a problem until you know you definitely have a problem and not a oddball one-off situation.

At least, that's the rule of thumb for most people with finite amounts of income. If you've got entire banks of money to burn, just start throwing parts at it until it goes away

[macuser27]

Originally Posted by soundman98

You just read the codes, but didn't erase them?

Codes are stored in the computer until a certain amount of drive cycles are completed. I don't know the number, but it's a lot, so even driving the car every day for 2 hours for a week isn't going to clear the codes by itself.

So all the codes deal with misfires.

First step would be to erase the codes, and see if they come back.

Second step would be to run a different tank of gas through the car.

How full was the gas tank on the last session?

Don't be throwing parts at a problem until you know you definitely have a problem and not a oddball one-off situation.

At least, that's the rule of thumb for most people with finite amounts of income. If you've got entire banks of money to burn, just start throwing parts at it until it goes away

Thank you.

Correct. I read the codes but not erase them. I'll do so and report back if the codes reappear.

I arrived at the track that morning with a full tank of Shell Premium (91 octane here in CA). I noticed the check engine light at the end of the third session. The fuel level indicator was around 1/4 tank. I brimmed the tank with Sunoco 91 octane at the track for the 4th (last) session and drive home.

I agree with you at not throwing parts at the problem. My mind went straight to coil packs as #2 and #3 (and #4) are at 71,xxx miles. Coil pack #1 was replaced at 25,xxx miles and again at 50,xxx miles based on the previous owner's service log. I'll hold off for now and continue the diagnosis. Thanks again.

[soundman98]

also be sure to check the fuel injector module bolts on the passenger side of the motor. some of those are used as grounds, and if they become loose, it'll result in engine run errors. i believe failure for the injectors to fire and inject fuel would also create a misfire situation.

it just strikes me as odd that 1 injector has 'failed' twice in 25k mile increments, and now you're experiencing a pair of cylinder problems at the next 25k mile increment?

lots of coincidences in that. parts generally don't fail that close to a predicable pattern over the course of 75k miles.

thinking broadly, there are a number of guys that experience fuel starvation on high-g turns. left-hand i think? i know verus sells a modified fuel flap door specifically for the purpose. but this is going to depend on the specific turns of the track you're running, and should be very predictable(should always happen on 'turn x' to determine if that would be the cause.

[Turdinator]

Misfires when tracking aren't an unusual thing. Do you have a tune on the car? Sometimes that will contribute. Replacement coils are the best way to fix it but you can also swap the coils that didn't misfire over with the ones that did and get a bit longer out of them before you need to replace them (since the coils ain't cheap)