why is my 2001 couger running like it has no power i changed just about everything and it still has no power and there is no light comeing on i have changed fuil rail, filter, plugs,wires,coil,iac,trans sensors,both o2 sencers,intake gaskits,tps, theres no air leaks idk what els to do but scrap it and lose i even had the main cat cut off, it pops when im driveing and sounds like pop corn but over 40 it runs fine but wont go over 70