Mechanics

WHAT'S THE PROBLEM?

1997 Ford Thunderbird • V8 2WD Automatic • 110,000 miles

I have two each, trouble codes P1151, P1132, & P0136, each registers twice? The check engine light also remains on. I have changed the power control module, the fuel pump assembly in the gas tank, and the two rear heater oxygen sensors.
What?
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Jpmaurice
July 24, 2011.




Wow replaced pcm? Well mayb still a wiring problem or the catylitic converter is bad


Tiny
Bobarezo
Jul 24, 2011.
Can I throw my dart at the board? 1151 is for an intermittent oxygen sensor signal. That is not how the sensors fail. Look at the wiring harness for wires rubbed through, loose or corroded pins in connectors, or the harness fell down onto hot exhaust parts.

1132 refers to the internal heater circuit in an oxygen sensor; again, not how they typically fail. More common again to suspect a wire harness problem, especially when there's two related codes.

136 means the Engine Computer isn't happy with something about the driver's side oxygen sensor behind the catalytic converter. The best approach is to view live sensor data on a scanner to see what's being reported by the sensor.

The Engine Computer is doing it's job recording the fault codes so I'm not sure why you would replace that. Same with the fuel pump. That has nothing to do with these codes. The first two codes are for the oxygen sensors in front of the catalytic converters, not the back ones that you replaced.

The catalytic converters aren't the problem either. The job of the rear oxygen sensors is to monitor the converters' efficiency and set the appropriate fault code when one drops below a predetermined threshold. A problem with the converters won't stop the sensors from doing their job.


Caradiodoc
Jul 24, 2011.
Thank you caradiodoc, your answer makes perfect sense to me. I replaced the fuel pump assembly before I knew the codes, based on the lack of performance of the vehicle. And then based on the codes I replaced the first two sensors I found, and when that didn't fix the problem I looked on the electrical diagram and saw the sensors fed into the pcm and that's why I changed that? Inexperience. After everything, I started looking to physically locate the other two sensors. And amazingly enough the sensor on the drivers side, I found barely installed, I could remove it by hand. I was going to replace it with one of the rear sensors I had removed. But they didn't have the same wiring? There was a tab, on the wiring socket that prevented me from plugging it in. So I just properly tightened the original sensor. It didn't fix the problem. But I have suspected that this sensor may have been damaged or ruined because it wasn't connected properly all this time. I think perhaps, according to your answer, I should replace this forward driver's side heater oxygen sensor and that could very likely resolve the issue. Thank you very extremely much. Please feel free to add any additional information and I'll let you know how it goes, thanks again.
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Tiny
Jpmaurice
Jul 24, 2011.
Before you spend money on a new sensor, erase the codes and see if the 1132 code comes back. If it does, use an ohm meter to measure the resistance of the heater. I never measured one myself but I'm guessing it will be less than 50 ohms. The point is, ... If you find an open circuit when measuring at the computer, recheck it right on the sensor's connector to see if it really is the sensor that's at fault or the wiring.

Code 136 could be related to the loose front sensor. In between the pulses of exhaust gas, the momentum creates pulses of vacuum that will draw in outside air. The extra oxygen in that air will keep the rear sensor detecting a lean condition. The loose front sensor will detect that extra oxygen too. The computer will respond by adding extra fuel in an attempt to achieve a proper fuel / air mixture, but no matter how much fuel it adds by the intake valves, there will always be that extra oxygen by the O2 sensors. O2 sensors don't detect unburned fuel, only unburned oxygen. You could potentially smell that extra unburned fuel at the tail pipe but the computer will still be thinking the mixture needs to be richer.


Caradiodoc
Jul 24, 2011.

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