Thanks a bunch for your responses!

I drove it to the office today. It stumbled a little bit around 4k and/or around 5k. I went out to lunch today and pulling out of the parking lot, I couldn't get the rpms over 1500. I turned it off and restarted it. It then seemed ok.

I won't be able to do much diagnosis until later this week. I'm hoping to avoid a trip to my mechanic, but it's not looking good as I only have a primitive code reader.

I noticed it idling somewhat roughly this morning (air temp 27 F, -3 C).