BlacknBlue just asked me by Private Message what the symptoms were when my cats went bad. I would reply by PM, but BnB has them turned off in his profile.
Symptoms included general loss of power, but unless you're testing or timing your 1/4 mile, how much power is lost is dificult to figure, and it really plays with your mind. Eventually, I knew something was definitely wrong when the PFE tube blew off the fitting under heavy acceleration. Had a new one reattached and clamped, and it blew off again. With the PFE tube blown, the 2.5L Mystique gets blown away by mopeds, speedwalkers, and your gandmother's electric scooter. It's dangerously slow to drive, and will not make it up hills.