Hello! I got a 1.0L 1997 K11 from my grandpa which was in need of a full service. I have changed everything on it, and took it for a test drive today. While driving it i noticed something weird. First off, the car has terrible pre ignition issues. For example, whenever i press the accelerator pedal more than 20% and put some load on the engine, the engine pre ignitions a lot. Although this might be because of old gasoline that is in the tank. The main problem i am more concerned about, is that the rpm's don't immediately drop (rev hangs) after every gear change. Also sometimes, whenever i put neutral when coming to a red light, the engine will stay running at high rpm and won't drop to 900-1000 rpm after 2-3 seconds. In some cases it will actually idle at 2000 rpm without dropping at all. When it idles at 2000rpm i turn the engine off, and the turn it back on and it will idle fine. What could the issue be? maybe a dirty MAF sensor? (air filter hadn't been changed in years) Was thinking on cleaning it, but on prefacelift micras i cant remove the MAF sensor from the throttle body housing. Any help appreciated! Thanks!