so friday after work i go and start my car, its a b16a in a 5ghb by the way... and the idol jumps up to like 2400, and then drops down to 1200 it does this for about 5 mins... and then it stays at steady idol at 1900 for bout 45 seconds and then starts the fluctuating agin... i have zex kit install'd on my car.. and when i just turn th box on.. no nitrous in the lines... the idol stays at a steady 2600, until i turn it off and it and fluctuates, so i was thinking of a vacuum leak.. but i can't find one.. i was also thinking MAP sensor..... but i doubt it since its not throwing the MAP code, or any code at all besides my normal Knock Sensor code. i thinking maybe head gasket but no sure... can anyone please help me.