05 impala drivability issue

the temp code, will have some thing to do with the engin not reaching op temp. in a time frame, for that check coolant level and thermostat working correctly, or just replace it.
did the misfire codes come back?, that's what's causing the stall.
you'll have to find out witch cylinder is causing the misfire and rule out what is causing that cylinder to misfire, plug,coil,wire, compression, ect...

is there an easy way to check the this stuff without taking it in? i changed the plugs and wires so ill look at coils next as easiest thing to eliminate?

you'll need to know just witch cylinder is misfiring and then swap over parts" plug,wire,coil" to a cylinder that isn't misfiring, if the misfire code goes to that cylinder, you'll know it was the part swapped that is causing it, then just replace it.

Jess,

You’re gonna have a problem here gettin this problem fixed, and that’s because everything that’s been posted so far (in the way of a repair) has been nothing but pure speculation. In other words guesses. Guessing at your problem is not fair to you, especially since it's your money that others here are guessing with. Also I see you have made a classically typical common error, and that is to just throw parts at your problem in an effort to try to fix it. Understand, that to haphazardly throw parts at a problem is a waste of your time and money. The proof of what I’m sayin is in your statements that appear below.

(You said) autozone checked and it read that the target temp was not being reached and also that there were multiple misfires. so i replaced

(You said) so i replaced the coolant temp sensor. spark plugs and wires. all fluids are filled to where they need to be. the car will still occasionally stall at a stop when in gear and will also have rough idle when in gear or park

If you want this problem repaired quickly and accurately post the actual error codes that Auto Zone read for you. I never guess at a problem. I deal only in hard facts and details, and those are two things that you should be extremely thankful for.

yeah.. i just had the codes read again and the first code was p0128 which was coolant temp not reached.. the next one was p0300..a random cylinder if that can help diagnose im all ears big block. thanks

Jess,

What's happening here is that PO300 set as a result of PO128 setting. It's not uncommon for one code to set another code. There could be several reasons for the setting of PO128, but for now we'll start you off slow and easy, and you gotta post all results. PO128 means that the PCM has detected that the engine has not reached the required temperature level within the timed threshold that the engine was designed for. First:

What's the condition of the coolant?

Is due (or long overdue) for a change/flush?

Are you using Dex-cool? If you are, then flush it out of the system, and use only the coolant coolant that appears in the link below.

http://www.peakauto.com/antifreeze-peak-global_lifetime.shtml

If your gonna flush the system the best way is to install a Prestone "Flush and Fill Kit" first. The kit is designed to be permanently installed, and assures you you won't be left with any air-pockets in the system. T also makes any future flush jobs easier. The kit is not expensive and you can buy it at any quality auto parts store. Make sure you follow the installation instructions exactly. For the antifreeze, like I said DO NOT use Dex-cool and use only the antifreeze in the link posted above. Also don't buy it prediluted. It's a ripoff because your payin for a gallon, but you're only gettin half a gallon, because the other half a gallon is nothing but water. Use straight full strength antifreeze. After the flush just empty the radiator, and fill it with the straight full strength antifreeze and just leave what is left in the block. The antifreeze will mix with what is left in the block as you drive the car.

Make sure the thermostat is operational (replace as needed).

Use an infrared thermometer on the the thermostat housing to make sure normal operating temperature is being meet.

Failure of the ECT (Engine Coolant Temperature) sensor is common for your year, make, model and engine size car, but that doesn't mean you just replace the sensor just like that. First check it to make sure it's defective.

the ect code will not make it stall, at worse it will just stay in "open loop", witch is a cold air fuel ratio, that would just cause a loss in fuel milage.
go after the misfire problem frist.

Jess,

(Quote) the ect code will not make it stall, at worse it will just stay in "open loop", witch is a cold air fuel ratio, that would just cause a loss in fuel milage. go after the misfire problem frist.

The above statement is 100 percent accurate and I agree with it. The thing is for your year, make, model and engine size vehicle, if the engine doesn't reach NOT (Normal Operating Temperature) within the timed threshold it was designed for, the engine will misfire. That's why I said (in the first place) that the setting of PO128 set PO300. Based on countless past experiences if you resolve PO128 first, PO300 should resolve itself.