lack of power or acceleration

I actually had the problem solved. There is a TSB (#05551: Special Policy Adjustment - Catalytic Converter - (Sep 14, 2005)for this model (and others) with a Catalytic Converter failing and blocking free flow of exhaust gases. The policy covers the condition described for a period of 10 years or 120,000 miles (190,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership. The repairs will be made at no charge to the customer. Unfortunately it may be too late for you, I just barely made it within the prescribed period. GM was very accommodating though with the repairs.

well, we just recently bought the car not even a month ago from a owner so i dont know if she had it taken care of when they did recalls or if she had any problem with it..i know my sis was driving down the fourlane and it just all the sudden lost power and now wont go faster that 25mph..but i have had alot of impala ownes tell me it is sensors and catalyc convertor...i guess we are stuck buying ever part new that can cause the problem..when it was put on computer the only thing showing up is the cooling fan #2 circuit...

thanks for advice. Actually had injectors cleaned prior to your answer, marked improvement in acceleration, still seem to have loss of power, especially between 30-40MPH