P0300 with only 57,200 miles?

scoobysnax · **Posted:** Mon Oct 26, 2009 10:04 am

I got a P0300 code yesterday. Three days ago after stopping getting out of store and starting the jeep up (engine still warm) it stalled shortly after I started it. I thought maybe I turned the key "off" to quickly and didn't let it turn over enough. Started again and this time it didn't stall but very close. Engine turns over up to 1,500 rpm (normal) and then dipped down to only 250 rpms before settling back at about 500 - 600 (my normal idle speed.) I use the car to run a few more errands and now issues. When I park it for the night after shutting it off I tried to start it again to see if I'd have any issues and it was fine.

Yesterday I start it - fine. Drive an hour stop and then 3 hours later leave - when starting it was OK, but slightly off. After stopping to run into a store and then starting again it had issues - back to 250 rpm but started. check the code and only the P0300 showed up - Random misfire of cylinders.

I am at 57,200 miles so I'm hoping it will still be covered under the warranty. Recently I had the rear rotors and pads as well as the E-brake pads changed out by a mechanic. At about 55,500 miles I had the dealer do some warranty work - transmission flash, replaced failed water pump, engine oil/filter change (synthetic) and installed Hella 500FF. I have an Optima Red top that is only about 8 months old. I had the charging system checked maybe 4,000 miles ago and everything was top notch. My spark plugs are at about 27,000 miles - I have not checked those yet.

I've done a search on this site and it seems like my problem could be a variety of things. HOWEVER it also seems like this has only happened to people with over 100K on the odometer. I'm worried that this has happened to me with less than 60K (although thankful I'm still under warranty.)

scoobysnax · **Posted:** Wed Nov 04, 2009 1:45 am

so a week later the check engine light went off. I had the apointment to bring it to the dealer and they said they couldn't find anything wrong - maybe a glitch in the computer. So I asked them to replace the computer, they laughed and said they can't replace a computer under warranty that says it's working.

So now I guess I wait.

tommudd · **Posted:** Wed Nov 04, 2009 9:20 am

P0300 mutiple cylinder misfire

more than likely some fluke when you started it.
What type of gas have you been running, how low have you ran it down
8 month old battery can be bad as well have seen them bad at 2 months, but this is not the problem here
not sure what you mean when you say this problem shows over 100,000 miles, it could turn up at any time.
27,000 miles on the plugs , its time to replace in my book.
No they will not replace the computer unless there is a major malfunction with it.

Albert · **Posted:** Wed Nov 04, 2009 11:55 am

Yeah, that's a random misfire code and you probably got some bad gas as Tom said. Especially if it went out. If you got 27,000 miles on the plugs it is time to change them. They are real easy to change and don't cost that much.

mikey1273 · **Posted:** Thu Nov 05, 2009 12:34 am

When I had Gas engine cars things like that would happen once or twice cus of bad gas.
I would not think 27,000 miles would be too long for a set of spark plugs, I was over that stuff pretty well and I never took the plugs out if they the engine was running fine untill they had over 30,000 miles, but then I used platinum plugs.

P0300 with only 57,200 miles?

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