2004 chevy trailblazer_ls
I've had my tb for like 3 months. Recently i started to notice that when i have it just running at idle in park position, it idles at about 600 rpms. But about every 3-4 minutes, the engine almost dies, dropping below 500rpms. Then it catches and returns to about 600. I have no idea what could be the cause. Any suggestions please!