poppin, wheezin no acceleration 2.4 L voyager

I have a 98 Plymouth Voyager, 2.4 L 4 cyl, 90K miles; hard to start for a year; harder when cold; sometimes take 10 minutes to start; when it does start it wheezes and puffs, and often pops and backfires; no power on grades or for passing/merging; will not take any throttle at all without bogging down; sometimes will stall when taking off from a light if not accelerated just right; have changed both O2 sensors; only other code was bad #2 cyl. wire; can hear fuel pump pressurize at start. Could cat be that plugged up at 90K miles? I can blow through fuel filter easily....I don't want to just start replacing sensors willy nilly.........Help!

Sounds like the timing belt slipped a tooth . If you have never changed it , it is way over due . Have the timing checked and the computer scanned for codes...

Timing belt was changed about 6 months ago (at 83k miles); started right up (normal) after it was changed (not an easy job getting to the front of the engine); does sound like some type of timing issue; can accelerate normall some times by downshifting manually to either 1st or 2nd; is there a tranny feedback for the timing in th e electronic distributer?