Already the forum helped me diagnose a rough idle problem. Whenever I put it in D or R, it would shake like crazy. It also had the check engine light on (after I replaced the bulb the previous owner had removed

). I bought a cheap OBD2 code reader and it was giving me 100, 110 and 420. I cleaned out the MAF sensor with electric contact cleaner, reinstalled and everything is fine. It idles smooth and no more check engine light. There's still a small rough spot rolling to a stop, but it's a lot better than it was.