i have a 2001 Cavalier z24.....i have a high idle(1500) because i used to have my Venom 400 chip hooked up.....and now that i put a new header(Tsudo) in when i turn it on when its cold it idles like normal then after a lil bit it drops down to like 500 and then kicks back up to 1500 then in a lil bit drops back down to 500 then kicks back....it almosts shuts of it goes down so low....im not sure what the problem is...no check engine light on or nothin....i think i need to get the idle reset but i don't think thats the whole problem...any thoughts???

i also forgot to mention that it stops doing it when the car gets up to normal temperature

Anything like what's going on in here