While driving i noticed the power was diminishing, i had to feather the gas to continue driving.I also heard a screeching noise which sounded likea fan belt .When i come to an incline, the car has zero power to make it up the hill now. Any suggestions as to what has happened or is happening to my vehicle??

 

losing power- 1st thing that comes to mind is a clogged catalytic converter.

 

alright this is something to check that i had forgotten about, but what about the "fan belt" noise i heard shortly after it started??

 

well, theyre no longer called fan belts. The old days the engine had about 3 belts- fan, alternator/power steering/ AC.
maybeeven 4. so the fan belt was specifically that- a fanbelt... nowadays theres 1 giant belt that connects all these items. The Serpentine Belt.
Like a serpent causeit winds like a snake.....

Alotof these Serp beltswill last a LONG time. The one in my Trailblazer is ratedfor 150K miles.... thoughIve replaces it for peace of mind.
It could be that the belt has glazed overin some spots. But if its doing this every cold startup- it may either be the one of the pulleys- or the belt itself.
You can test this by grabbing a water bottle(spray). When you turn on the car and can sort of pinpoint the screech- spray some water on the belt- see if the noise goes away. if it does- then you know its the belt.
If it doesnt- thenit may be one of the pulleys.

 

It could also be the belt tensioner that's noisey.

 

im with rbarrios, same thing happened to our car, its a bum catalytic converter. no power and noisey as hell

 

i know this is late reply, but here goes...
i bought a 2001 impala ls, used of course, anyway about 2 months later i experienced the same as you describe.
my problem turned out to be 2 coils had gone bad, this caused no power nad under stress it made a nasty noise.
my chevy dealer fixed me up real nice, no charge.

 

been hearin the stories bout the power loss & I been told the CAT/CONV is to blame in "most" cases,, we dont have E check no more so I figure I can just cut it out from there & put a piece o' flex pipe or even a solid straight pipe & some clamps.. so i'm gonna give it a go & let you'all know what it does..only 65000 miles , it should not act like this...wish me luck...

 

well if you are down a couple cylinders - you will still have A problem...just no longer a clogged cat.

 

When my 2001 Impala had a clogged cat, I was travelling down the Pennsylvania Turnpike and my speed dropped to 35 in the center lane with 18 wheelers whizzing by on both sides of me. There were no strange noises other than a ratchet wrench type sound when trying to step on it to get the heck out of there. I called onstar and they did an online diagnostic and told me everything was fine. When I finally got it pulled over I had my wife get behind the wheel and elevate the engine speed. When she did this, there was no exhaust gas volume to speak of coming out of the tailpipe.