2006 nissan xterra if a catalytic converter can cause multiple miss firing and lose power while accelerating?

SOURCE: 000 NISSAN Xterra -- after warming up, loses RPM by 500-1000..... have replaced ignition wires and distributor, checked mass air flow sensor and OK.....

I had a problem on my Nissan Xterra 2000. Symptons sound similar. In my case, it ran fine for a while and then suddenly the engine starts to stumble and lose output. At one point it did not even have enough HP to move. Irregular idling too. Thought it was water in my fuel. Bought water remover from the store and added to gas tank. Problem did not go away. Instead, "Service Engine Soon" light came on. Had to have it towed to the dealer as there was no way the engine could keep up with traffic. Dealer replaced the "Crank Position Sensor" today. Parts $33.00, Labor: $300 (about 3 hrs worth of work). Seems to work fine now but I will wait and see. Dealer also stated that Distributor bearing appears to be noisy and will need to be replaced sooner or later. I will wait for it to go before I fix that.

SOURCE: catalytic converter still glowing red

When running does the engine shake back and forth (indicating a skip in the engine) also does it rev up freely. If you were to rev it up to 3500RPMS would it be smooth without the engine shaking back and forth? Also the o2 sensor on the front of the exhaust manifold is pretty easy to get at, if you were able to pull that( 7/8") wrench I beleive) you could tell if it were running rich (sooty black color). In the end you could take it to a muffler shop and for very little money have them inspect your cat, without any cutting or welding. a $20-$30 cost at most. I know the fixya wants us to be self suficiant but even i don't mess with small exhaust work because of the benieft of not dealing with it, especially for such a small price. But if its something you wanted to do, I could explain so. A shop can visually inspect the cat, and see if it is clogged with oil, or excessive fuel. At any rate in the end if they do find that you do need a cat, don't buy a GM one, there are plenty of other sources for an aftermarket cat. IF you decided to go that route i know of a few sources that one could be had for pretty cheap ($50-70) for new. Let me know if any of this helps

SOURCE: multiple random miss fire

Now change the distributor. Get one from salvage or e-bay. Did the timing belt jumped a tooth or is it new. Vitally

SOURCE: do I need a catalytic converter

Yes but there could be other causes. A sticky fuel injector, bad fuel pump etc. Other signs of a bad catalytic converter are a smelly sulphur exhaust, a very hot exhaust throwing heat from the middle of the car. Unless there's a lot of miles on your car, I'd be surprised if it were a bad Cat. Hope this answers your question. Best of luck.
Greg

SOURCE: 1995 GMC Safari Loses Power when accelerating hard, rough idle

your egr valve might be faulty bring it in to the auto parts to have it check out what your looking for is the 32 code on the OBD II scanner.