K7VZ
03-21-2011, 01:28 PM
Guys, help me out on this.
About 2 years ago, my XJ started throwing a P0141 (http://www.obd-codes.com/p0141) code. I replaced the bank 1, downstream sensor and that fixed the P0141 code.
About 1 year ago, it started throwing the P0155 (http://www.obd-codes.com/p0155) code. About the same time, a friend was doing an engine swap and had an extra set of O2 sensors he didn't need that were good when he pulled them. I put the used O2 sensor in bank 2, upstream.
I still get the P0155 code once or twice a month. For the last year, I've just been resetting the computer and keep driving it. Finally, I got sick of doing that and bought a new O2 sensor and installed it a few weeks ago. Guess what? I'm still getting P0155.
It seems to throw the code when the engine is cold. IE, when I first fire it up within the first 2 minutes of idle.
Anybody know of what I should be looking at next? That O2 sensor is new and the wiring harness/connections look good.
P0155 - 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
This code refers to the front oxygen sensor on Bank 2. The heated circuit in the oxygen sensor decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it. The ECM tracks how long it takes for the oxygen sensor to begin switching. It the ECM determines (based on coolant temp) that too much time elapsed before the oxygen sensor began operating properly, it will set P0155. See also: P0135 (Bank 1).
A code P0155 may mean that one or more of the following has happened:
* O2 Heater element resistance is high
* Internal short or open in the heater element
* O2 heater circuit wiring high resistance
* open or short to ground in the wiring harness
About 2 years ago, my XJ started throwing a P0141 (http://www.obd-codes.com/p0141) code. I replaced the bank 1, downstream sensor and that fixed the P0141 code.
About 1 year ago, it started throwing the P0155 (http://www.obd-codes.com/p0155) code. About the same time, a friend was doing an engine swap and had an extra set of O2 sensors he didn't need that were good when he pulled them. I put the used O2 sensor in bank 2, upstream.
I still get the P0155 code once or twice a month. For the last year, I've just been resetting the computer and keep driving it. Finally, I got sick of doing that and bought a new O2 sensor and installed it a few weeks ago. Guess what? I'm still getting P0155.
It seems to throw the code when the engine is cold. IE, when I first fire it up within the first 2 minutes of idle.
Anybody know of what I should be looking at next? That O2 sensor is new and the wiring harness/connections look good.
P0155 - 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
This code refers to the front oxygen sensor on Bank 2. The heated circuit in the oxygen sensor decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it. The ECM tracks how long it takes for the oxygen sensor to begin switching. It the ECM determines (based on coolant temp) that too much time elapsed before the oxygen sensor began operating properly, it will set P0155. See also: P0135 (Bank 1).
A code P0155 may mean that one or more of the following has happened:
* O2 Heater element resistance is high
* Internal short or open in the heater element
* O2 heater circuit wiring high resistance
* open or short to ground in the wiring harness