Cylinder 1 Misfire P0301

[lkz6678]

While changing the oil in my 2015 Sonic I made a mess and spilled oil on the plastic engine cover. Two days ago I sprayed degreaser on the engine cover and scrubbed off the oil and then poured water over it to rinse it off. Yesterday I noticed the engine misfire a couple of times. Today it is misfiring so badly the car is almost undriveable.
I plugged in my Ultragauge scanner and it shows a "pending code" of P0301, "Cylinder 1 Misfire Detected".

1. Is it possible that I poured water into something and that is causing the misfire? If so then why didn't the water burn off from the engine heat? I pulled off the plastic cover to look under the coil packs and there is no water visible.

2. It has 45000 miles, could it be that my spark plugs are going bad already? (I just bought the car used 2 months ago.)

3. Why is the Check Engine Light not on, and what is the difference between a "pending code" vs a "trouble code" on the Ultragauge scanner?

Thanks for any help!!

 

[rojoes]

Doesn't sound like a plug but since it was bought used you can check it and coil packs are not that much if you possibly damaged it. Is this a 1.4 or 1.8?

 

[gnonne]

I'm not sure how you spilled so much oil on top of the engine - these are designed for pretty clean oil changes. Anyway, I've got three Sonics, one with about 90k miles on it. No misfire issues and never replaced any plugs yet. Maybe there is some oil between the coil pack and the plug?

My daughter's Buick misfired for a while before it threw a light on - turned out to be a loose plug wire. But, these newer cars don't really have wires, so I'd investigate what is between the coil and the plug.

Given that it started right after the spill and cleanup, its probably related to that somehow.

 

[lkz6678]

I had to unexpectedly go out of town for 37 days. Just got back, the car has been sitting idle all this time (I disconnected the battery before I left, wasn't sure how long I would be gone).

I took the car for a 2 minute test drive, the CEL is now on and flashing and the P0301 is a regular code not a "pending" code. I still am not sure what a "pending" code means.
So I will go to Autozone today and buy a Delco 41-122 spark plug and replace spark plug #1 and see if that fixes it.

During my 2 minute test drive around the block I also got a warning on my Ultraguage code reader about my battery voltage being too high: 14.92V. That's strange, no idea what is going on there.

Also the yellow Traction Control dashboard warning light was on. That is the first time I've seen that light since I bought the car.

 

[lkz6678]

I replaced spark plug #1 and there was water around the spark plug and the electrode area was black. I looked at the other spark plugs they looked ok (and no water). Replacing the spark plug did not fix the problem, engine was still misfiring.
I took the coil pack out and noticed there was water around spark plug #1 again. Must be coming out of the coil pack.
Bought a new coil pack at O'Reilly Auto Parts for $106+tax and that fixed the problem, car is running normal again.

My lesson learned is don't spray water on the engine because it might destroy the coil pack! Although how that happens, I have no idea.

 

[OssiansFolly]

Yea, these coil packs are iffy sometimes and if you happen to have problems where the code comes back...downgrade the spark plugs back to OEM plugs. For some reason, these packs/engines have issues with better plugs.