Engine running rich, code P1132

Good morning,

I have attached a list of possibilities for the engine running rich for you.

Start with checking for any vacuum leaks, fuel leaks, or exhaust leaks as any of them could trigger this code.

Can you tell me the long-term trim percentage reading from your scan tool?

Roy

Hello, do you have access to a scan tool that can read live data? The first thing to check would be the fuel trim numbers, most likely if the oxygen sensors have never been changed on this truck, it's a failing front oxygen sensor, but it good to check things out first. If you do have live data take a look at what the short term and long-term fuel trims are at. And also look at the front oxygen sensors. If either of the front oxygen sensors are stuck at any particular voltage, that is a problem. The front oxygen sensors should have a swinging voltage from 0.200 to 0.800volts. Thats how narrow band oxygens sensors will look on live data. If on the front oxygen sensors heater circuits have failed, the sensor will be inactive. In this case since you're getting a rich code, the engine computer is seeing an oxygen sensor that is reading close to 0.800v. Thats a rich condition. Most likely you would also see fuel trim numbers that are negative.
When the engine computer (ECM) sees a rich condition, it will start to subtract the amount of fuel from the air/fuel mixture, thus a negative fuel trim number.
You can also check the heater circuit directly at the oxygen sensor.
I'll put the wiring diagram below, but for the front oxygen sensor (Bank1 sensor1) the heater circuit is the red/white and the red/yellow wires, if you unplug the sensor and put a multimeter across these two wires coming from the sensor you should have somewhere around 3-30ohms of resistance. If the heater part of the sensor has failed, you will most likely read OL on the meter. Meaning it's an open circuit and the sensor has failed.
There can be other causes of a rich condition too but starting with looking at the fuel trim numbers and the front oxygen sensors activity is where to start.
A dirty mass air flow sensor, misfiring cylinders can also cause a rich condition. Taking a look at the spark plugs to see if they are covered in black soot will also show that the engine is actually running rich and it's not just a faulty sensor telling the ECM it's a rich condition. Write down any fuel trim numbers you can get. or take a picture of the live data on your scan tool if available.

https://www.2carpros.com/articles/how-an-oxygen-sensor-works

https://www.2carpros.com/articles/how-to-test-an-oxygen-sensor-02-sensor

It is most likely something simple. Just need to narrow it down to a particular area.

Roy

Sounds like a plan.

Roy

You need to repair that and make it leak-free. Otherwise, the sensor sees all that extra air and it could be the cause for the reading on the sensor.

Roy

You are welcome.

Always glad to help.

Feel free to ask any questions.

Roy