P0101 Exhaust EGR Flow Inefficient
The quick description of P0101 is a mass airflow (MAF) circuit or performance malfunction. When the MAF signal is below a certain spec that is when the P0101 appears. Bill Fulton first wants to talk about the mass airflow sensor, it’s the major input in a computer. It will calculate the load, injector on time, and spark timing. So, it’s very common for these mass airflow sensors to malfunction, and many times what we want to focus on is the fact that you may have a customer come in and want to try cleaning it. Bill shines a flashlight on the air temperature sensing element, which without a doubt can get contaminated and insulate itself from the actual intake air temperature sensor. This would cause the engine to run rich. When cleaning the MAF it is important to use the right chemical to clean it. MAF cleaning fluid or electrical cleaning fluid is the only thing you should be using to clean it.
Bill reminds us to keep in mind that the MAF is a major input in the computer to calculate injector on time, calculate load, and spark timing. For these reasons, its obviously very important input to the PCM. What we find in the industry is that these sensors cause the engine to run lean, meaning a lack of power type conditions.