Rough cold start on 2009 hyundai genesis 3.8

[Thegenesis2009]

After the car sits overnight or for long period of time the car will start rough and will shake and idle rough for about 15-30seconds. After about 15-30 seconds the car returns to normal idle and the car runs fine the rest of the day. I got a code once before and it ran multiple random misfires. Just curious if anyone has had happen to them.
Thank you

 

[toxicavenger70]

Are you using the OEM oil filter? And what kind of oil are you using?

 

[decolamber]

So my car has a small misfire and rough idle on start up, I’ve replaced all 4 spark plugs and coils.. the misfire is still in cylinder one.. when I removed the plug I noticed it was a different color than the rest and the cylinder was a little wet.. I’m wondering if it’s possibly a leaky injector but wanted advice before spending more money.

 

[princelybug]

So my car has a small misfire and rough idle on start up, I’ve replaced all 4 spark plugs and coils.. the misfire is still in cylinder one.. when I removed the plug I noticed it was a different color than the rest and the cylinder was a little wet.. I’m wondering if it’s possibly a leaky injector but wanted advice before spending more money.

I suggest replacing the remaining 2 plugs while you're at it. Might as well.