I have bought my car as a salvage at 97,000 miles back in 2001 for $2000. It now has 211,000 miles and was running great until recently. My check engine light came on about a week ago,and I have been noticing the motor being flat on power. Replaced the plugs and wires w/o improvement. My CAT has not been changed out since I have owned it,but it has been rattling and has been breaking up inside over the past year. Should I let the CAT ride for now and try replacing the O2 sensor off the manifold first to see what happens? Or should I try to find the MAF sensor and clean it with the electric component cleaner first? I have noticed a decrease in fuel mileage as well. Been a grerat car,just want to keep taking care of it and get it thru another NYS inspection in April.Thanks for the help, Jack.