Re: 2004 grand cherokee 4.7 three codes
It looks to me that you have two separate problems:
1) The O2 sensor fault code and hydraulic cooling fan fault code. Both the O2 sensors and the hydraulic cooling fan use the same fuse, #16 in the PDC under the hood. If there was a short in one of the O2 sensors, than the fuse is blown and the new sensors and fan control donīt work. So check fuse #16 first.
2) You say that you unplugged a pump, but did you mean the EVAP/purge solenoid? Fuse 21 on the junction block is from the EVAP/purge solenoid. This solenoid starts pulsing after a few minutes of engine operation and should keep a certain vacuum in the fuel tank. It can be that it stays open with the fuse 21 in place and creates a false air entry into the inlet. The P1495 code however has to do with the leak detection pump. I would errase the codes, plug the EVAP/purge solenoid line for trouble shooting and see which codes come back. If no codes come back, you will have to see if the EVAP/purge solenoid maybe stays open.