Overnight, cold start hesitation.
 

For the past two mornings when I have started my car, I have noticed quite a bit of hesitation. In fact, upon startup the RPM's reach a max of only 1200 and bounce between 1k and 1.2k. 10 seconds later RPMs drop to 900. Normally the car would reach around 2k and settle to 900 after 30seconds.

I scanned for codes and this came about:

2 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16685 - Cylinder 1 Misfire Detected
P0301 - 35-00 - -


A little history about the car. Pass-side Primary 02 sensor replaced last year. Spark plugs replaced 10k ago. Coolant temp sensor replaced 20k ago.

The car has about 83k on the clock. Ambient temp outside during morning startup has been around high 40's.

Other than the hesitation, the car runs fine.

How do I go about fixing this? Replace the coilpack? Replace primary side 02 sensor?

Thanks.