so now im really confused. when i turn it on the idle is normal, but when driving and i engage the clutch the rpms fall to like 300 and it sounds like i tap the throttle but the computer does it by itself. then it comes back to normal idle. what is going on?
i'm not familiar with the codes, but I am familiar with seafoam.
it will loosen carbon buildup, and now your Jeep is trying to flush out the gunk. It might take a while, but then again some of it may get stuck in your O2 sensors.
I'm sure some knowledgable members will chime in, but I thougt I'd share what I know while you wait.
Sometimes seafoam can foul plugs or O2 sensors, especially depending on how it was applied. Did you use it through the gas or a vacuum hose? I'd pull the plugs and inspect/maybe clean or replace them. I think indication of such a fouling of the plugs would be a white/gray powder all over the tip of the plug
Now you've learned why not to use that junk - especially sucked in direct like that.
P0300 means you have, or had, random misfires temporarily. Most likely it fouled the plugs, the PCM detected it and won't forget it for awhile, even though the plugs are cleared now. The O2 sensors probably got polluted from that stuff too.
Remove the battery cable for at least 8 hours to clear the memory, not just the CEL.
Start it - don't just sit and idle - drive it immediately. Drive it like normal, not hard, not easy.
Cleaning the memory puts the PCM back to default. Driving it immediately will help it relearn, driving it before it gets into closed loop helps it run a little rich, then when the O2 sensors heat up the crud burns off - hopefully.
Also check the vacuum line that you used - make sure both ends are on tight.
Next time - put it in the tank only if you really feel the urge.
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