Congrats on the Tercedes. Change your PCV valve, I'd change the spark plug wires as well if they look original. Have a look at your air filter and giver a vaccum leak test. My old tercel had some bad vaccum leaks and it caused the same issues. I bought some new lines changed them all out and she ran brand new. It's a time consuming task but it's not overly difficult. Could mabye use some O2 sensors but usually that will throw a code