Thank you very much to both of you for your responses. It’s an LE, 4 cylinder, 85,000 miles. I did neglect the maintenance for way too long, about 2 years, 15K miles, before last December. I don’t think it’s burning oil though.
The work in December did include replacing the spark plugs. The shop’s writeup about this says “In-Line4-including fuel injection cleaning and throtle body cleaning and adjustment”.
I’ll see if I can find out the brand and type tomorrow.
I might also mention the check engine light has been on for months. In Dec. they said it was a problem with the evaporation system but it wasn’t something that needed fixing right then. (I had a bunch of other things that came to $700, so I wasn’t eager to fix anything that wasn’t a real problem.) Just mentioning this in case there’s any possible relation to misfiring or it really should be fixed.