What is A Mass Air Flow Sensor?Īir Intake System with Mass Air Flow Sensor It can also cause premature failure of the catalytic convertor if left un-repaired. If there is too much fuel getting into the engine, this can end up in the exhaust fumes and could cause a noticeable gas smell coming from your exhaust pipe. Gas smell from the exhaust pipeĪ failure to deliver the exact amount of fuel to the engine, will affect the fuel to air ratio in the combustion chambers. Similar to the previous point, if you are driving uphill, towing, or demanding power from your engine, you will find a serious hesitation due to lack of proper information regarding air mass entering the engine. This condition will be worse under wide open throttle acceleration. That process could take half a second to a second, more than enough to perceive the hesitation. In such a scenario, the ECU will sense the drop in engine vacuum first and then using other sensors, will decide if more fuel is required. Engine hesitation during accelerationĪ bad mass air flow sensor won’t reliably measure the amount of air coming in through the air filter, resulting in a delay in the fuel delivery during sudden acceleration and a temporary lack of power. This might cause a rough idle or even an engine dying occasionally while idling. Rough Engine Idleĭepending on the vehicle year and maker the ECU may not compensate for this failure during idle. This is not an accurate value and will result in more fuel being fed into the engine than is required. Most ECUs will revert to a default air mass value range to keep the engine running. Without proper information coming from the MAF, the ECU won’t be able to operate efficiently and thus, a noticeable decrease in fuel economy will be evident. On older models, you may find that the engine doesn’t start at all. Depending on ECU’s program sophistication and installed sensors, the vehicle start can be very difficult. Since the ECU can’t measure incoming air mass, it needs to compensate for this lack of information using the rest of the engine sensors. This is because the ECU will detect an out of range value coming from the MAF sensor and the check engine light is its way of letting you know that something is wrong. Check Engine Light appearing on the dashboardĪ bad mass air flow sensor will usually trigger a check engine light. Here are some of the most common bad mass air flow symptoms that you will typically come across. Therefore the most common signs of a bad mass air flow sensor usually appear in the form of an engine that is performing badly. It must be able to accurately measure the air flow and send this information to the ECU in real time. This is why the mass air flow sensor is important. The amount of fuel must be kept in line with the amount of air coming in. In order to increase speed, more fuel and air is needed. If you push down on the accelerator, the engine will need more fuel to increase the rate at which the pistons are moved. The amount of air entering the engine through the air filter is going to fluctuate depending on how fast the engine is running. The mass air flow sensor (MAF) data is vital for fuel delivery control.
DURAMAX LB7 MASS AIR FLOW SENSOR PROBLEMS HOW TO
Of course, there are many other reasons why your car might not be running properly, so today I’m going to explain how to diagnose a bad or failing air flow meter and see what’s involved in fixing it. If the mass air flow sensor isn’t working properly then you will be faced with one or more symptoms such as lack of power and bad fuel economy. The job of the mass air flow sensor is to keep track of the amount of air coming in through the air filter, so that the ECU can adjust the amount of fuel getting into the engine. Cummins bad wastegate symptoms.The symptoms of a bad mass air flow sensor include low engine power, poor fuel economy, an engine that won’t start, a check engine light on the dash and a gas smell from the exhaust fumes.Ī bad mass air flow sensor is often the likely culprit if your car isn’t running as it should.