MAF sensors and Oxygen Primary sensors

My Australian Spec 1999 model runs excellent with one MAF(s) disconnected ! I replaced the one that registered as failed but now again I am having problems revving beyond 3000rpm ( ! ? ) Is it always advisable to replace both MAFs when only one is showing up as failing ( and then affecting the 2 primary 02 sensors which I have already replaced ! )Thanks...............Kennyghttp://forums1.roadfly.com/preferenc...php?img=135692

K & N Filter oil on MAFS has turned out to be the culprit !http://forums1.roadfly.com/preferenc...php?img=135692