I have a 2001 Grand Prix GT Coupe Limited Edition that has 108,000 miles on it that is now hesitating on 1st and 2nd gear, only when warm....It never hesitates or feels sluggish when cold.....Mechanic told me it was my Catalytic Converter but I don't believe them.....going to change my plugs and fuel filter, neither of which have EVER been changed....Any ideas? The hesitation feels more like the engine is getting choked off and sputters until I let up off the gas....Any help would be greatly appreciated!