2000 Impala Mass Air Flow Sensor

Its not the MAF. It came on because air flow was low due to engine running below 400 rpm. Without know what engine is in you car its a waste of time to say more.

Good engine. Start with the usual - clean the throttle body area. If you take it off to clean it, then remove and clean the IAC as well. Clean the MAT (temp sensor). The pcv valve is probably ok but may be worth replacing or cleaning. If that does not work then you will have to start diagnosing the problem. Check the plug wires with them HOT (temp). Check the ohms or volts at the TPS. Post back your results and readings.

if what he suggests doesn't work, then yes, the MAF being bad can cause the symptoms you are describing. if you're handy with electrical, & you can determine which wire is the signal wire, you can check the voltage on that wire, while putting the engine under a load (car in gear, brakes applied, caution being the key). as the engine goes from a light load (idle in gear) to a heavy load, (throttle opened a ways with brakes applied fully in gear) the voltage should change smoothly & steadily. if it suddenly goes to 5v+ (max) or near zero, or at any point fluctuates (i.e. irratic movement) then it's worn out & needs to be replaced. with the amount of miles you said being on it, it's a very likely candidate for being worn out.

This MAF sensor doesn't output a varying voltage, so your test is useless.