trouble shoot

Hi I own a 1999 Ford explorer v6 sohc 4.0 287024 miles. Does not want to hold above 2000 rpms and when you push the gas pedal down towards the floor the engine will not take gas and will not acclerate. Getting codes including o2 sensor and MAF sensor, cut my cats off one was bad got some power...

Ok, so I replaced the shift motor on my transfer case (94 ranger stx manual hubs push button 4x4). That was simple. and 4 wheel drive worked. But only for a while. I dont know what happened in between it working and not working however I am getting different symptoms this time. 1. buttons...