tru

my cars a 95 wrx i thought my lamba sensor was playing up fitted a universal one but did not seem no different. now got the original back in but if you unplug it at the connector it does not make any difference to how the car runs is this normal or is not working also over the last couple of days on initial start up it has been lumpy for a couple of seconds then clears i don;t know if this has anything to do with the lamba thanks