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Q: MAF sensor, fuel injectors, check engine light, cylinder

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How do I know if I have a bad MAF sensor and the fuel injectors?

It takes a professional mechanic to check those components. If your vehicle has a Check Engine Light, start by getting the codes read. If the codes say you have a MAF sensor or a fuel injector problem, that will show you which system(s) needs to be addressed. But it takes years of experience and very expensive equipment to figure those things out. If you don’t know how, have a mechanic diagnose your Check Engine Light for you.

What a skilled mechanic will do is plug in a dealership-quality scan tool and analyze the MAF data. That data can be very complicated, so it takes lots of experience to understand it. We use freeze frame oscilloscopes and have tables on our data system that show what’s a good sensor reading and what’s a bad reading.

This process can be very complicated, and with fuel injectors, it’s the same thing. If you have a code for a problem on the cylinder number three, then you can simply take the number three injector and switch it with number one injector. Then if the code changes to a number one injector, you’ll know that the injector’s bad and to replace it. That’s a simpler repair you can try to do yourself, but the actual testing is very complicated and only an experienced professional can do that.

If you want to have a technician look at this for you, a certified mechanic, such as one from YourMechanic, can inspect your Check Engine Light and any other issues that you are having.

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