O2 code help!

Doomedfailure

Member
Jul 1, 2009
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I have a 1996 mustang GT that has a 2003 motor swapped in it. Still uses uses coil packs and all the 96 hardware. I have a problem with my check engine light and the codes are as follows. Also I got the O2 simulators thinking it would help but it did not. Also I do not understand how the sensor two can read bad if I have the simulators.

The Codes:

P0136 oxygen sensor circuit bank 1, sensor 2. (see P2270, P2271)

P1151 Heated Oxygen Sensor Bank 2, sensor 1 switch point lean.

Also did anyone clips not line up on the O2 simulators? mine did not on the passenger side so I clipped them off.
 
Doomedfailure:

I am not very good at tracing electrical faults but I'll try to help out.

P0136 is a 'circuit fault' is for the after cat converter sensor on Bank1 (passenger side). (Bank 1 is the side with Cylinder #1 on it, or, the passenger side for our GT's. Bank 2 is the driver side.) The sensor is not working (failed sensor) or there is a wiring issue with the harness on the car or the harness on the sensor. The O2 sensor simulator (MIL eliminator is what I call it) could be faulty. You can try swapping the MIL eliminators to see if the fault moves to the other side. Then you will know if the MIL eliminator is bad. If you are using the 2003 intermediate pipe with [2003 model year] O2 sensors then the O2 sensor plug may be pinned differently than the '96 harness. In this case, you can try to re-pin the O2 sensor or just get sensor(s) for a '96 GT. Sometimes, the rear O2 sensors have to be shut off in the tune. Let's see what happens with the MIL eliminator check-out before worrying about the need for a tune.

P1151 is a lean code for Bank2 so you most likely have a small exhaust leak on the driver side side IF P1151 is the only code posted when BOTH front O2 sensors are working. If they are both working and you get another lean code (P1131 for lean on Bank1) and that means (usually) there is unmetered air entering the engine or you have exhaust leaks on both sides.

HTH,

Chris
 
Doomedfailure:

I am not very good at tracing electrical faults but I'll try to help out.

P0136 is a 'circuit fault' is for the after cat converter sensor on Bank1 (passenger side). (Bank 1 is the side with Cylinder #1 on it, or, the passenger side for our GT's. Bank 2 is the driver side.) The sensor is not working (failed sensor) or there is a wiring issue with the harness on the car or the harness on the sensor. The O2 sensor simulator (MIL eliminator is what I call it) could be faulty. You can try swapping the MIL eliminators to see if the fault moves to the other side. Then you will know if the MIL eliminator is bad. If you are using the 2003 intermediate pipe with [2003 model year] O2 sensors then the O2 sensor plug may be pinned differently than the '96 harness. In this case, you can try to re-pin the O2 sensor or just get sensor(s) for a '96 GT. Sometimes, the rear O2 sensors have to be shut off in the tune. Let's see what happens with the MIL eliminator check-out before worrying about the need for a tune. P1151 is a lean code for Bank2 so you most likely have a small exhaust leak on the driver side side IF P1151 is the only code posted when BOTH front O2 sensors are working. If they are both working and you get another lean code (P1131 for lean on Bank1) and that means (usually) there is unmetered air entering the engine or you have exhaust leaks on both sides.

HTH,

Chris



I am using my exhaust from the 96 GT and magnaflow cat backs. the O2 sensors were replaced when i replaced the motors. but i will try switching the eliminators and see if the code switches. I really hope it is not the wiring. I know the pins on the two O2 sensors are different the pins look the same but the one purple and the other blue and the do not have clips in the same spot. I am guessing the one up front is an exhaust leak since it is on the one side, and that make sense. Thanks! I will try that all out