08-18-2022, 10:01 PM | #1 |
Drives: SS Join Date: Aug 2019
Location: California
Posts: 25
|
P0300 and P0308 help
So this morning i drove my car to work and it felt fine then i felt like it began to sputter or miss. eventually the car threw a CEL and a stabilitrak error. I could tell the car was not firing on all cylinders. as i drove it home it would clear up intermittently and run fine then it would miss again. it cleared up a few times before i got home but ultimately the CEL was still on and i could tell it wasnt firing on all 8. My car did sit a few weeks prior to this. I ran my scanner and saw codes p0300 and p0308 misfires on cylinder 8. i swapped the coil to cylinder 2 but i never cleared the first code but when i rescanned there wasnt an issue on #2 so possibly not the coil. The plug on 8 looked fine. i dont know if this is a reliable way to check plug wires but i measured the resistance and #8 was the same as some of the other wires. any thoughts on what else i can do?
thanks |
08-19-2022, 06:02 AM | #2 |
Drives: 2017 2SS, 50th pkg, M6, MRC, NPP Join Date: Jan 2016
Location: Ocean City, NJ
Posts: 3,177
|
Is car modified?
Doubt it's plug or wires. Check oil for any particulates or glitter suggestive of cam/lifter wear. Would hook up a scanner and check fuel trims. Possible bad fuel injector on #8. |
08-19-2022, 11:36 AM | #3 |
Drives: SS Join Date: Aug 2019
Location: California
Posts: 25
|
Should have mentioned that. Yes it's modified msd intake, rotofab, 95mm TB, tuned for e85
|
08-19-2022, 01:12 PM | #4 |
Drives: 2017 1SS 6spd Join Date: Jan 2011
Location: Utah
Posts: 2,869
|
Any room in the tank to top it off with fresh premium? Remember- KISS! Hopefully its a simple fix.
|
08-19-2022, 01:51 PM | #5 |
Drives: 2017 2SS, 50th pkg, M6, MRC, NPP Join Date: Jan 2016
Location: Ocean City, NJ
Posts: 3,177
|
I would check the fuel trims.
Given the number of intake modifications, I would first guess air/vacuum leak causing the misfire. maybe the intake at the one corner since #8 is giving you trouble. |
08-19-2022, 06:20 PM | #6 |
Drives: SS Join Date: Aug 2019
Location: California
Posts: 25
|
I had just put new gas in it since it was pretty empty. Well now I'm very confused. I replaced the injector and the problem was still there. Now I'll admit I should have done this first and tried new plugs as it's least expensive but I did not think the problem was a spark plug due to the problem being intermittent. But here's why I'm confused, I switched the #8 and the #1 plug and now the car runs fine. No missing or sputtering and no CELs. I don't know why it would work in one cylinder and not the other
|
08-20-2022, 04:50 PM | #7 |
Drives: 2017 1SS 6spd Join Date: Jan 2011
Location: Utah
Posts: 2,869
|
Oh the unsolved mysteries and vagaries of life... Enjoy the ride while it lasts- and don't worry, be happy!
|
09-17-2022, 09:30 PM | #8 |
Drives: Corvette Join Date: May 2016
Location: New Albany
Posts: 45
|
I had the same problem. Ran the car hard one night. The next day car ran like shit. Had codes p0300 and p0308. Changed plugs and wires and all is good.
|
|
|
Post Reply
|
|
|