StealthFormula

iTrader: (35)

I have a check engine light for P0161 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 2). I have a 24" Oxygen Sensor Extension connecting to the 02 Sensor because of the LT's and I know that the two brown wires are the wires for the heating circuit. Could it be one of the brown wires on the Extension are not getting enough voltage to the 02 sensor? Any ideas?

keliente

iTrader: (22)

The code is for the second o2 sensor, which, if you have an off road y pipe, is unnecessary. Looks like you've had your PCM tuned - head back to the tuner and have them remove the rear 02 codes. They may have missed one.

StealthFormula

iTrader: (35)

Its for the passenger side front O2, I had the rears deleted a while back. I thought bank 2 sensor 2 is the front passenger side I guess I made a mistake I mean bank 2 sensor 1.

keliente

iTrader: (22)

It may mean the sensor has just gone bad. Coated headers have a way of doing that!

35thANNIz28

what?!?!!? how can coated headers mess up o2s.......i have the same problem...i use the same 24'' extensions and new o2s so i really doubt that headers will mess em up... its probably the wires...too damn long..i shouldve got 1 12' and 1 24' for the drivers...but everynow and then it turns off n on

StealthFormula

iTrader: (35)

I've heard before that when you first put headers on some of the coating inside I guess heats up and melts off or something along those lines and can mess up the 02 sensor. Same with me, the code shows up then goes away but its in memory with the scan tool so its always there eventhough it may not be showing the check engine light.

Domesticated Euro

iTrader: (1)

If it shows up sometimes and not others, it sounds like it could be a connection problem. If I remember right, the O2 heater sensor will set the check engine light imediately, where if it is just the sensor, that's a different story. The best way to check it would be to turn on the ignition and use a DMM to probe in the Connector for that O2 heater. Find out which 2 wires are for the heater circuit. (DO NOT PROBE THE O2 DIRECTLY!) with the ignition on, you should have 12 Volts on one of the wires and 0 Volts on the other, Do not worry about the other wires. If you have 12 Volts on both wires, then your O2 is bad. If you get 12 Volts on one side, and 0 Volts on the other, then shut the car off and disconnect the O2 sensor connector. Probe the same 2 wires at the connector end and check for continuity. If it is open, the O2 is bad. If you have continuity, then the O2 is good and you have a problem with the wire to the PCM. The PCM needs to see the voltage drop to recognize that the O2 heater is working.

I may be wrong, but that's how I would check it. I've had problems with my sensors before too.
Good Luck,
Luke

StealthFormula

iTrader: (35)

thanks alot, Im going to try that and see what happens.

keliente

iTrader: (22)

Happens more than you might think. The new coating burns off and it fouls the o2's. Sometimes a week later, sometimes a month later...if I plan on using new o2's with coated headers, I usually run my old ones for a couple weeks first just in case.

blk97z28

iTrader: (3)

I have a bank 2 sensor 1 malfuncting, and it is my PS 02 sensor going bad. I used the stock one again on that side after 73,855 miles when i did my headers. I am just going to replace the PS 02 sensor and be done.