recurring 02 sensor code

[gonzo]

03 Wrangler Sport 4.0 auto. Hard starting engine and missing when running, got PO155 code (02 sensor heater malfunction bank 2 position 1) and cyls 1&4 misfire codes, replaced both upstream 02 sensors and spark plugs and cleared the codes, jeep ran perfect for a couple of days then hard starting and missing again and PO 155 code is back. Any help would be greatly appreciated.

 

[SteelHeadz]

Please Check this for any Relevance to the condition on your Jeep. 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

 

[Snowrdr01]

I actually just threw the P0141 code last night on my first drive after putting a rolled jeep back together. I figured it would just be the O2 since i know they are delicate but now i would like to check the fuses first. I checked my chiltons manual but i couldnt figure out what fuse is responsible for the 02 sensors, where are they located?

 

[SteelHeadz]

Here are 2 Schematic diagrams that you can use as reference. Note: PDC is the fuse box in the engine compartment. Junction Block is the Fuse box behind the Glove box.p0p

 

[Snowrdr01]

thanks for the help but in an odd twist i got under there yesterday to find that both upper o2 holes are plugged. There is another further down the header before the cat but i thought that was my down stream o2 sensor? I looked around for a good ten minutes and found no random plugs in the engine bay. I guess a picture of the engine bay pointing out where the o2 sensor wire comes from would be a help so i could try to figure this one out.

My thoughts were A the POs trail jammer taps the o2 sensor or B this is an aftermarket header and relocated the o2 sensor?

 

[Snowrdr01]

i tried to post pics but i need a few more posts

 

[Snowrdr01]

here is number 4 post

 

[Snowrdr01]

now the next one i can get the pics up, thanks for sticking with me

 

[Snowrdr01]

pic

 

[SteelHeadz]

Chasing Ghost. that's a twist alright. the Wiring for the 02 sensors should be in the harness with the injectors, TPS , map. I didn't see any catalytic converters on your pics. does it have them?. I use to live in LasVegas and i know that you have Smog testing. did that change?

 

[Snowrdr01]

it doesnt have the mini cats on the header but i wasnt sure if that was only equipment for the CA emmissions jeeps since i dont remember mini cats on my 97 tj but i sold that a few years ago so i could be wrong. I wasnt sure so thats why i thought it might be an aftermarket header that relocated the o2 further down. In the second picture you can see the flange right after the sensor, thats my main cat, it was the same as my 97. But yes we do have emmisions down here in TX and i will be headed there tomorrow. Im pretty sure itll fail the first time since i cant imagine 2 year old gas burning too well. I filled it up on monday after i got my plates to try to dilute it.

 

[gonzo]

All the fuses are good and none are missing, checked both fuse panels.

 

[Snowrdr01]

miraculously the CEL was gone when i brought it to inspection yesterday and it passed, im checking the fuses this weekend when im in it for oil and spark plugs