the check engine light will not go off. another test was done and it shows that we should ceck the circuit fuse relay, were can that be found on the liberty jeep 2004,code P0038
I replaced all four of the oxygen sensor and the check engine light will not go on 2004 Jeep Liberty
To have all 4 go at the same time is very unusual, if not impossible. The O2 system on this Liberty has the power to it controlled by the PCM. The P0038, "HO2S Heater Control Circuit High" tells me that there is power being delivered to the heater circuit and the problem lies either internally in the sensor, or it is a ground issue. Disconnect all the sensors and on the body side of the connectors, check the black with orange stripe wire for continuity to ground using an ohmmeter. If 1 or more show no ground, you can either trace the wire back through the harness to find the break, or just splice in another wire to the black/orange and connect the other end to a good ground point. All 4 sensors share a common ground point. If the grounds check good, with the ohmmeter, check each sensor for heater operation. There should be continuity through the heater. The wire colors are as follows, sensor 1, bank1, brown/orange to black/orange. S1B2 brown/white to black/orng. S2B1 and S2B2 brown to BLK/O. If any of the 4 have no continuity, change that sensor. If all checks out good, with key on, engine off, check for power on pin 4 of each sensor, if no power, repair open circuit(s).
Take your Jeep to the repair shop and let them fix it!! One that has a good 'professional' scanner would be nice!