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2007 Kia Spectra Missing When First Warms Up

I just replaced the ignition coil as recommended by the computer and the car ran fine for a few days. Now it starts missing about a mile after starting, for a while. Then it almost never misses after it is fully warmed up. The computer does not find any issues at this time. Do you have any suggestions on what the issue is?

Thanks

Here’s some advice.
A misfire fault code (P0301 for example) doesn’t mean that coil #1 is definitely bad.
Here’s some other possibilities:
spark plug
low compression
faulty fuel injector

Those fault codes just narrow things down for mechanics. A mechanic would say, “Okay, I know the engine’s running rough because #1 is misfiring. I’ll concentrate on that cylinder.”

I’ve had several instances where the misfire was not caused by a coil. There was a recent Ford that had a bad injector. It wasn’t plugged. It had infinite resistance, meaning it was electrically open.

So my point is, the car needs to be diagnosed.

Please hook up the scanner and post any stored codes.
I’m assuming you cleared codes after replacing the coil, right?