Is it air flow meter malfunction?
Car does not take off like it used to...I have changed fuel tank,fuel filter,and
new spark plugs and still the same...
Could be, these are very sensitive units, any kind of crud in them really slows the response time down, also make sure the air tube from the sensor to the engine is sound, no leaks. You may want to do a compression on the engine, if it is getting low then you will also notice that take power will suffer.
https://www.youtube.com/watch?v=aDlHCjgYf8s If check engine light is on, you should get the codes scanned as well. You may have a bad cat that will rob you of power also. Check all of your vacuum lines, PCV, and EGR valves as well. Take a water bottle and mist down your plug wires. If you have bad wires, you should notice a drastic change in how the engine runs. If done at night, you should see a spark jump from the bad wire.
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