Hello All,

I own a 2003 Impala LS with 102,248miles as of 10minutes ago. My problem started three days ago. The vehicle accelerated from a stop and when the speed reached 24-26mph it felt sluggish, hesitation, like it wasnt getting enough fuel. I eased off the accelerator slightly and reapplied the gas and it picked up but it still had that hesitation about it. On the highway you could feel the roughness of it trying to get to 55mph. I attempted to pass a vehicle but when I pushed down on the gas it was hard for it to make 60mph. My vehicle will keep up with traffic, but it does NOT have the "get up and go" it had 3 days ago.
My gas mileage has been suffering as well. I usually average around 27.4mpg, but this last week it dropped down to 22.6mpg. I dont know if this has anything to do with the problem at hand, but the AC and Cruise Control having been giving me grief as well. Some days when I start the car the "CRUISE" light will be on, but my car is in park. When I turn the CRUISE off, the AC or HEATER (season depending) will come on. Also, a few timeswhile driving with the CRUISE engaged at 60mph, I turned on the Heater and the AC disengaged, but the CRUISE light was still on. My ABS and Traction light come on when I start the car and stays on even after I've started driving. Most of the time I will turn the car off, wait a sec, and start it again and they stay off. The ABS and Traction lights started coming on the same day of the acceleration issues.

My car had a tune up 2 weeks ago. I follow the book (Haynes) on the recommended Preventive Maintenance and there have been zero codes. This is my first brand new (16miles) car when I was promoted (Army) so it has been taken care of.

Thank you for your time.
Polymer

 

A clogged catlytic convertor will cause the symptoms of losing power.........
while youre going along easy the exhaust flows ok.
When you step on the gas to go faster etc- the exhaust cannot get out fast enough thru the cat- and you have this loss of power.
essentially its breating in lots of air- and it needs to start exhaling out the fumes- but it cant- so it bogs down.

imagine- youre running- youre breathing thru a toilet paper tube then change that for a straw.......... all of a sudden you cant run as fast.............. silly example.....

but you should look into that..

as for the lights?????

 

^^^ I agree. Are you wanting to mod it anytime soon

 

I had this same problem on my 03 LS about 6 months ago and it had about 90,000 miles on it. I drove it on a 300 mile round trip with this problem (it wasn't too bad when I started the trip, but it got worse as I went) and barely made it home before I got the cat. converter replaced. I was going through Illinois though, so it was mostly flat, but I had trouble getting up even the small hills.

Never had the cruise problem you describe though, that sounds electrical, or sensor related. That shouldn't have anything to do with the cat. converter problem.