Hello, everyone welcome to Hans garage. Today. I am going to explain two of the fall codes that I got yesterday. And if you don't know how to use an obd2 scanner, I will link my video that I've made yesterday. So you could watch it and learn how to use the obd2 scanner when the engine check light. Turns on. And before I explain two of the fall codes, which are p0 171 and p0 174, I'm going to explain how the engine works.
And then we will go from there. Ok? So, as soon as you turn on the engine, air is being. Sucked through the air scoop, and it goes into the air filter cabinet, and there gets filtered because your engine wants clean air, not dirty air. And it goes through this MAF sensor, which calculates how much oxygen is going into the engine. And then it goes through the intake elbow boot through the diesel valve and then into the intake manifold through the fuel injectors right into the cylinders and then spark plugs right on top of the cylinders will spark it up right after the air being compressed. And then it goes out into the exhaust system.
So right now I have to fall codes, which are p0 171 and p0 174. So 171 is Bank 1 system running to lean. Firstly, there's 1 2 3. And then 1 7, 4 is Bank 2, cylinders 4 5, 6 system running to lean. So what does it mean? If the system is running to lean? So right now there are 4 oxygen sensors in total and each catalytic, um, there's, two catalytic converters for this engine.
One for bank 1. So and there's 1 2, 3, the second calendar converter for bank 2, cylinders 4 5, 6, So each chaotic converter has two oxygen sensors, one, right before the catalytic converter. And then one right after the catalytic converter so there's, four of them. So if the system is running to lean, it means the oxygen sensor is detecting too much oxygen and less fuel.
So right now, it's less likely for the two oxygen sensors for each calendar, converter to go back the same exact time. So I'm, assuming there is vacuum leak within the intake system. So MAF sensor, calculates how much oxygen that goes. Into the engine, but if there's a vacuum leak, it means there's more oxygen, that's being calculated by the MAF sensor is going into the engine. So there's more oxygen coming out, right, so I'm, assuming there's a vacuum leak. But if not I might switch out my oxygen sensors, but my last resort would be the MAF sensor because this can miscalculate how much oxygen is going into the engine. And not enough fuel is going into the engine.
So this might be the last resort for me to clean it out or replace it. And this is the most expensive part someone I'm, not going to touch it just yet. So right now more to figure out if there's a vacuum leak by just assembling everything making sure everything is fit and tight. And then if everything is good here, then I'm going to check my oxygen sensors,