Have a d15b jdm spec engine and had it tuned recently (iacv cleaned, tps on factory spec, tb cleaned, new plugs) and also had my oil changed.
Weird thing happening now is that during cold start, it starts up fine revving around 1.3k RPM but when the RPM goes down to like 1k - 900 RPM, my idle starts to jerk with or without the a/c turned on. This will continue till like driving for 10 mins. Sometimes after releasing the throttle, idle will drop to 200RPM and sometimes it even dies down. Once it dies down and I try to restart the engine, it takes a few try before I can start the engine and even when it starts, it will stick to like 200 - 300k RPM for like 1 second before it goes up to normal idle.
Again, the mentioned problem only happends during cold start up and it goes away after running the engine for like 10 mins and even if I kill and restart the engine after 10 mins, everything works fine.
What could be wrong?