P0300 only at WOT

[Jared]

I've been getting an intermittent CEL and I am trying to track it down, Friday I was able to get ahold of a scanner and it showed history of cylinder 2 and 6 for misfires.

anything look off?
first scan showed the CEL at 4300 rpm, got another one around 3500 rpm

Going to swap coils around, the scanner showed history on Cylinder 2 and 6 only for the misfires, but the CEL was only a p0300, not cylinder specific

 

[Khaos]

I get that same code and haven't been able to pin point anything yet. Swapping coils around could help narrow it down

 

[2005_Silverado]

No LTs or cam? Those can set off P0300

 

[Jared]

Stock cam, jba shorty headers. It's thrown the code for me 5 or times, as soon as I let out of the throttle, it goes away. My ST trim is said to be off some

 

[Jared]

Anyone else?

 

[Samuel6731]

I get them here there in the CC...
Eventually i just set the CEL not to come on for that code
:shouldershrug:

Id try changing plug wires, just because they look good doesnt mean they really are

 

[Ginger]

i was gonna say i would swap plugs and wires since they are semi cheap.

 

[Jared]

I get the concept of them being cheap. And I felt the wires, I should have explained better. I plan on replacing the wires anyhow, but since the problem ONLY occurs at WOT, I doubted plugs and wires. The ST fuel looks off from what I saw doing a Google search, not off by a huge amount, but off. I'm thinking it's more to do with fuel or a lifter or valve.

And just clearing and not worrying about may work for you, but I have no desire to destroy my motor. I don't beat on the car, just passing someone on the highway the other day caused it to come on.

 

[j.mo]

I get them here there in the CC...
Eventually i just set the CEL not to come on for that code
:shouldershrug:

Id try changing plug wires, just because they look good doesnt mean they really are

You're cammed. So your p0300 code in this discussion is irrelevant.
P0300/misfire on a stock motor imo needs to be tracked down and addressed.

Like others have said, start with ignition related parts, plugs, coils, wires.
If the problem doesn't follow, I'd look into something timing related.

 

[Jared]

The odd part, and I wish I took a pic of it, was that cylinder 6 had like 260 hits, and cylinder 2 had like 180, or something like that. I'm going to order wires mainly because oem wires touch two spots on my headers (not the cylinders that have misfires). I'll be swapping coils and see if I can get the CEL to hit again.