Rough Idle, now Check Engine light on?

Okay, I'm back after lots of driving this summer. No real change in baseline behavior. To recap: some vibration when idling in gear. The temperature never gets above about 175 even in broiling summer heat with the A/C maxed. Also noted that MPG was never better than 24 even on long highway jaunts.

Misfiring issue has been completely cured.

So, I'm definitely planning on addressing the coolant and thermostat: flushing the coolant and converting it to Gold, during the process of replacing the thermostat.

Only work to report - the A/C was serviced, and the climate module was found to be faulty by my shop. I was able to find a used one for a decent price and replaced it myself. Much better than playing Goldilocks with turning the A/C on and off, which is how the summer started.

Also, I can confirm that the stock 2010 2.5L i4 has been programmed to be limited to 112 and I have no plans to do anything about that. Rides smooth and steady all the way up and anymore, I'd just get myself into legal trouble although there appears to be no interest in implementing any enforcement on the NJ turnpike these days. Limiting factors are my nerve, my tire quality, and the ECM. Will add updates when available.