Scanned my CEL on my 96 Tacoma 2.7 and it came up with P0125 Closed loop fuel control insufficient coolant temp and P0141 O2 sensor heater malfunction bank one sensor 2. Anyone have similar problems? I think it is my second 02 sensor. Could that be causing both codes? Any help appreciated.

THanks!

 

I have a 99 3.6 V6 Cali. When my front A/F went I had both the coolant temp and heater code for that sensor--there is a resistance check you can do on the heater. I am sure there is one for yours but I don't have it or I'd give it to you. Anyway, my A/F sensor tested bad and replacement cured both codes. Good luck, I'm surprised you aren't getting more help...must be the holiday.

 

Tomorrow I'm driving up to Burlington to try and swap some parts with someone getting their tacoma crushed. If it isn't too rusty, I'm going to try and get the AF sensor off. Is the AF sensor the just the O2 sensor in front of the cat? I can't really find anything in the manual on it. Hopefully I can just swap it see if that fixes it (after I get my oil pan fixed).

THanks!

 

bank 1 sensor 2 is the aft cat

good luck trying to jack one, better off with a new one

 

The 02 sensor behind the cat? I think that may be the one that has a small leak.

 

Sorry to have confused you, mine has an A/F before the cat; yours has an O2 before and after. Same function, but different electrical characteristics. I just wanted to share my experience that the sensor heater code and that catchall coolant temp code can come and go together. o2 sensors are not all interchangeable between engines, years, front/back, Cali/Fed., auto/manual,4WD/2WD etc. Know what you are putting in will match or you may have problems. Click here for the definitive list of sensor applications. Good luck..

 

I'm Having this problem and am getting tired of replacing parts. WHAT IS A/F SENSOR?? I have replaced my catalytic converter, front 02 sensor, thermostat and fluic is full. PO125 keeps coming back.

 

Here is directly from the factory service manual on your code P0125.
Open or short in A/F sensor (bank 1 sensor 1) circuit
A/F sensor (bank 1 sensor 1)
Air induction system
Fuel pressure
Injector
Gas leakage on exhaust system
PCV valve and hose
ECM

if you want the pages from it I can post them and you can print and download them. Sounds like it can be a lot of different parts. I would check the PCV first since that is the easiest. The A/F sensor is the O2 sensor before the catalytic converter. Did you put a Denso or an NGK sensor in it?

 

I used a denso part. I'll have to check the PCV tomorrow.
Thanks

 

i thought id bring this one back since im having this problem as well. i was reading on ttora that the A/F sensor is usually the culprit. ill link the thread but does anyone have anything to add to this? i only have one code being thrown up and it turns on and off intermittent, which makes me think its a faulty sensor.

http://www.ttora.com/forum/showthread.php?t=70150