Hi guys, I got a used Suzuki Swift 2007 (1.3L Petrol engine) a month ago and it is my first car. I am experiencing a rough idle when in neutral. There are oscillations in the tachometer +-400 RPMs. This mostly happens when I am stuck in traffic. At first, I thought the spark plugs were the problem and changed them, but the issue persists. Has anyone experienced the same problem? Any help/suggestion is appreciated! Thank you in advance!