e36328itopless

car is e36 328i convertible..4 weeks ago it started to idle bad about 500 rpm it drives good pleanty ov power..but when i stop it idles bad and sometimes stalls..its an automatic and its gettin on me nerves..loool...been told it could be loads ov things...icv maff 02 throtal sensor etc....changed maff last week new one..ok for a bit now back again..also when maff is disconacted all is ok think this is down to engine mangement running a preset mode..gona av it put on computer to see if there are any codes but havnt got eml on so not sure if it will show any...been lookin on web and it seems e36 is swarmed with this prob....any help would be great...thanx....also my airbox sensor is missing could this cause this problem...thanx again