Multiple Oxygen sensor failures in 99 XJ

[Its a jeep]

My Cherokee has gone through 6 O2 sensors in about 8 months. The trouble started when a few brackets broke off of my exhaust, causing the wires of the downstream sensor to rip off. The upstream burned out shortly after. I replaced both sensors with Bosch sensors, but the check engine light came on days later, for the new sensors. I ignored the problem for a while, and the engine light would go off for 3-4 days every other month. I returned the bad sensors and got two identical ones. I also had to replace the Throttle Positioning Sensor because that went bad too. About two weeks ago I replaced all the sensors. The next day the engine light came back on for the downstream sensor, then a day later the Jeep threw a code for the upstream sensor.

The recurring codes I've been receiving are:
P0135, P0138, P0133, P0132, P0131, P0136, P0137, and the code it threw for the TPS was either P0121, or P0122, I can't remember.

I would be really appreciative for any solutions, I live in New York, and I cannot renew my NYS inspection because of the emissions test.

 

[SteelHeadz]

Recent quality analysis has revealed an issue with repeated repairs for the same Diagnostic Trouble Code (DTC). The DTC may be due to an overlooked open circuit used to power the component in question. In most instances, either the circuit fuse has been erroneously removed or the fuse itself has an open (blown).

The component in question, and its circuit, are often protected by two fuses. It is usually the lower amperage fuse that is either missing or open.

The lower amperage fuse is positioned electrically in the circuit between the component in question and either a relay (Auto Shut Down, O2 heater) or the ignition switch. The lower amperage fuse will be located either in the underhood Power Distribution Center (PDC) or in the instrument panel Junction Block.

The lower amperage fuse is often missing because it was removed erroneously for use in another low current circuit. If the lower amperage fuse is open (blown), then the circuit and component in question must be checked for an electrical short. Check to make sure that the open fuse was not exchanged with another fuse or was damaged by an installed accessory.

NOTE: IF AN OXYGEN SENSOR IS REPLACED, VERIFY THAT THE CIRCUIT FUSE IS GOOD. AN OXYGEN SENSOR HEATER, WHEN DAMAGED OR OVERHEATED, MAY SHORT THE CIRCUIT AND CAUSE THE FUSE TO OPEN (BLOW).

The higher amperage fuse should be checked, but is not normally the cause of the DTC. The higher amperage fuse is located in the underhood PDC. It is positioned electrically in the circuit between the battery and either the relay (Auto Shut Down, O2 heater) or the ignition switch.

Refer to the applicable Diagnostic Procedures Manual and/or Service Manual (Group 8) for further technical assistance.

The following is a list of the components frequently replaced erroneously due to an open fuse. Included are the possible DTC(s) which would be generated as a result.

Oxygen Sensor (O2)


P0132 ($3E) = 1/1 O2 Sensor Shorted to Voltage
P0135 ($67) = 1/1 O2 Sensor Heater Failure

P0138 ($7E) = 1/2 O2 Sensor Shorted to Voltage
P0141 ($69) = 1/2 O2 Sensor Heater Failure

P0152 ($42) = 2/1 O2 Sensor Shorted To Voltage
P0155 ($7C) = 2/1 O2 Sensor Heater Failure

P0158 ($7F) = 2/2 O2 Sensor Shorted To Voltage
P0161 ($7D) = 2/2 O2 Sensor Heater Failure


Leak Detection Pump (LDP)


P1495 ($B7) = Leak Detection Pump Solenoid Circuit


Evaporative Purge Solenoid (DCP)


P0443 ($12) = Evaporative Purge Solenoid Circuit


Torque Converter Clutch Solenoid (TCC)


P0743 ($0C) = Torque Converter Clutch Solenoid / Trans Relay Circuits
This may help. if not let us know.

 

[Its a jeep]

That would make a lot of sense if the problem is a fuse. Do you happen to have any fuse box diagrams that show which fuses go where? For both boxes, the one inthe engine bay, and the one under the dash?

 

[SteelHeadz]

No i dont. sorry. it should be in the owners manual though.

 

[Its a jeep]

Okay, Thanks so much for the information, I will check the fuses, and let you know if It fixes the problem.

 

[mud4feet]

There's a diagram here:

Jeep Grand Cherokee WJ - Fuses

.........................oops, sorry, it's for a Grand

Here's another link from another board:

http://www.automotiveforums.com/vbulletin/t183822.html

 

[Its a jeep]

Okay, So. There was a blown fuse. It was a smaller 15 amp. In the hood fuse block. It was the only fuse that was bad, I pulled them all out and checked them. This is the one that was replaced. I'm not sure If it is the O2 sensor because I didn't have a diagram for the fuses under the hood, but It is the only one that was bad. Hopefully It fixes the problem. Will know in a few days when the monitors reset.