Exhaust/back pressure problems?
 

Hey, does anyone know why my 1991 Supra[turbo][automatic] became really sluggish after having a cat-back exhaust installed?{exhaust specs: 2 1/2 in. pipe w/ super 40 flowmaster muffler}. I lost alot of low rpm torque and my car's velocity at around 55MPH takes longer to hit 80s or 90MPH. I nearly have to floor it for it to get going. it doesnt have the power and torque it had b4 when I had the stock exhaust system . Should I install a cold air intake? boost my turbo from stock 6-7lb to 14-15lb? install a down pipe? please let me know

Arrrggghhh. Wrong muffler for a turbo vehicle, replace it with a straight through design. Have you seen the inside of that muffler?

http://www.flowmastermufflers.com/images/_40_super.jpg