2020 Chevy silverado 1500 l84 5.3 10spd sporadic p0300 misfire

Michael Ruch · May 31, 2020

Customer complaint

- flashing check engine light under light throttle check engine light flashes for roughly 10 seconds.

2020 Chevy Silverado 1500 5.3 10 spd

bone stock

has 3800 miles on it

first time bringing it in they pulled the codes and said that you have a p0300 random misfire 28 counts on cylinder 8. Cleared codes and moved on.

Drive the truck 200 miles and light comes on again (flashing).

pull codes and have p0300 again cylinder 8 120 counts.

Ill attach pictures of the freeze frame data.

Seams to run good only complaint is chugging under light throttle when going 40-60 range

Very upset about this.

Edited May 31, 2020 by Michael Ruch

1997SierraSLT · May 31, 2020

Welcome to GM ownership. Get used to P0300 because you'll be seeing that flashing CEL for years to come.

Michael Ruch · May 31, 2020

13 minutes ago, 1997SierraSLT said:

Welcome to GM ownership. Get used to P0300 because you'll be seeing that flashing CEL for years to come.

Is this a common problem? I wonder if they are working on a fix. I wonder if it truly is misfiring or just a soft ware problem

Sector7500 · August 2, 2020

I am wondering if you have had any solution or update to this issue. I may be having the same problem over the past few days. Flashing check engine light for 10 seconds or so, no noticeable issue. Dealer found store misfire code. Happened again a few days later.

Pinnacle · August 3, 2020

On 5/30/2020 at 8:55 PM, 1997SierraSLT said:

Welcome to GM ownership. Get used to P0300 because you'll be seeing that flashing CEL for years to come.

This is all I need to see to tell me youve been around GM for along time lol

SierraNoob · August 9, 2020

Hopefully I'm done dealing with this problem for awhile but mine just had to have a dfm solenoid replaced and I've been battling this issue since 800 miles and I'm at 4300 now.

Sector7500 · August 10, 2020

On 8/9/2020 at 4:51 AM, SierraNoob said:

Hopefully I'm done dealing with this problem for awhile but mine just had to have a dfm solenoid replaced and I've been battling this issue since 800 miles and I'm at 4300 now.

May I ask how it was determined that a DFM solenoid was at fault?

The dealers I have brought it to are a bunch of code resetters and "unable to duplicate." No real effort.

SierraNoob · August 10, 2020

Sector, I opened a case with gm because I had other issues but after the 2nd time I brought it in for the mifire and they couldn't replicate it they opened a case with gm and got help from their support. First time after that they had it for a week and they couldn't duplicate it and the second time I brought it in a couple days after that gm support told them what to replace I guess.