I've had both of these problems, I have 192K on my '02 impala - and it runs well. I've had many frustrations, but the car has never left me stranded anywhere. Most of the problems have been annoyances & inconveniences. I live around Cleveland, so the snow and salt in the winters takes its toll. It's a base model, but it has a spoiler on the back, sun roof, alloy wheels, pin stripes, CD & cassette player,. ... I still like the way it looks.
My driver's side master window control was hardly working - I took it apart (it was like peeling an onion - it had many parts I had to keep removing until I got to the actual metal contacts) and found that the metal contact were all "carboned up". I used an "electrical spray can contact cleaner" and a Q-tip and they cleaned up easily. I put it back together and it worked great, but be careful not to break the small parts when disassembling. be careful to put all back in reverse order and all of th parts back in the same orientation that they were originally in.
When my blinkers only worked half the time, I tried many things - the only thing that worked was replacing the 4-way emergency blinker mechanism.
I have also had the BCM replaced ($430 from a repair shop, not a dealer) when many electrical things went bad in a short period of time. It's under the dash on the passenger side. They had to program it and make sure it was the correct part. This fixed many things - daytime running lights, air conditioner, electrical "engine-front fans", ....
The entire transmission was replaced under warranty at 35,500 miles - its been fine since. I had the intake manifold gasket replaced (like everyone else) at 94K miles.(I was hoping GM would reimburse me the $400 I paid for the job, but apparently they don't do this). I also had to replace the inside rearview mirror (the cheap plastic tab that flipped it from day to night vision broke). I replaced the two rear exterior door handles after the hinges broke (very cheaply made).. My fuel guage usually doesn't work, so I use the trip odometer to tell when to fill up (the sending unit is in the gas tank and was much too expensive to fix for an older car).
Since the 2001 is the same as the 2002 through 2005 impalas, I can get most of the newer replacement parts at a very reasonable price from used parts stores who have disassembled newer impalas that were in accidents.
Even though the car is 7 yrs old and has 192K on it, it's a great car because it's paid for (its also dependable and I still like it). With the gas costs exceeding $4.00/gallon now, I am spending more on gas that I'd like, so I'm delaying starting any new car payments. BTW, I still get 29 MPG on the freeway and 24 or so around town.
Next thing I need to do is replace the interior fan resistor (its under the dash by the passenger side, next to the fan, which is in a type of canister), because "speed one" does not work on my heater/A/C fan. I'm also toying with the idea of replacing the two driver side door hinges, as they are shot and make a loud cracking noise when I open the door 1/2 way (even though I have been greasing the hinges for years).
I also noticed that the top front of my engine is covered in a light layer of oil. I thought the valve cover bolts were loose, but they're tight. so, the oil must be blowing out from the "oil fill cover" for some reason - something must be blocked up?
Hope this helps you. If anyone has info that would help me, I'd appreciate it.
Thanks,
Bob