ok i need help i cant figure out what this could be. i have a 02 bonny ssei and when i put the car in park after driving the engine revs up and down from 700rpms to 1500rpms for maybe a full min then smooths out. now i do have a trouble code of MAF sensor low voltage how can i fix this? Where is the MAF sensor located?

The MAF sensor is located directly on top of the throttle body. Its black and square looking. Should be 2 screws holding it in and a 3 wire connector.

Replace the MAF sensor first, then we can move on to the idle issue, but I'm pretty sure the idle issue is related to the MAF.

OK now today my car died on me on the side of the freeway (and it just so happened to wanna snow) but as i was driving when i press the gas the engine would lag badly and when i let off the gas the engine would idle fine. i figured i was lo on gas because my gas gauge doesnt read accurate ( i know the fix for that just havent had time) but after i added the gas i get about 2 miles down the road and she shuts off on me and wouldnt start up again. is this a related problem or something new because I was told it could be the throttle position sensor or the MAF I tend to rely on the advise i get from this site so please lead me in the right direction cause i gotta make it to work monday

Read this over, then I want you to do a few things.
Part 1 -MAF Sensor Test (P0101, P0102, P0103): GM 3.8L (1996-2005).

If you do not have a multimeter than can read Hz, then at least test your MAF Power, and Ground wires for damage, or corrosion, then test each if you have a multimeter.
If you have a multimeter than can read Hz then you can also test the MAF signal.

After you test the power, and ground wires, I'd remove the MAF, and examine the tip of the MAF, if that plastic tip that covers the thermistors is loose or separated from the MAF, then remove it, and discard it, as it can cause you to stall out, and not be able to restart the car if loose enough to spin around inside the TB.
Then clean the MAF thermistors with some MAF Cleaner, and see if that helps.
If not unplug the MAF and see how it runs, if it runs better then replace that MAF, even if it does not run better I'd get a new MAF, then let us know how it runs.

I am with Mike, my money is on it being a bad MAF, they are a bit pricey, but easy to replace.

A maf can make a car not run....???

Normally it will just make it run rough unless it has totally failed, if the MAF is not getting any signal sent to the PCM, then yes it can make the car not run.
The tip on my MAF had separated from the MAF, and it was able to spin around for a while, which caused me throttle issues, and occasional rough starts.
Eventually the two little dots/tiny plastic pins became worn down, and the tip would spin constantly causing more severe idling and throttle issues, from time to time the tip would get stuck sideways, that prevented the car from running.

ok so i changed the TPS yesterday and the MAF today and all i get is cranking so i checked the fuel pump to see if it was sending fuel and it is i checked all fuses and relays and still the car just cranks. what now?

Engines need 3 basic things to run. Air, Spark, Fuel.
Obviously the engine is getting the air, so we need to make sure its getting spark and fuel into the cylinders.

I'm confused, why did you replace the TPS sensor? A bad TPS would usually throw a check engine light, but a MAF sensor usually does not unless it completely fails. Reinstall the old TPS, and leave the MAF disconnected. Attempt to restart the engine.

This nightmare is on going!! ok today i tested the MAF for power and ground and both check out fine my multimeter doesnt read hertz so i couldnt test that but still no start. other that that one thing that caught my attention is when i turn the key in the Driver info center the message Service theft system is displayed i never seen that before and dont know why it would be. As i read some other post here i hope this problem is not a ECM problem i guess the only thing left to check is my injectors, how do i do that? and how can i check the pressure from the fuel pump?

There is a port on the fuel rail with a schraeder valve for hooking up a pressure gage. Looks just like the valve for putting air in your tires.