2000 durango was driving fine then seemed to lose power and die and won't restart easily. It sputters and backfires, occasionally will rev up but won't idle on its own. What do I look 4?

What is the actual code number? If it is actually a cat code and you have had it for three years I would start there. Cat probably all stopped up now. And what you are discribing as symptoms sounds just like a stopped up cat. Use caution failure to replace or remove a stopped up cat can lead to your vehicle going up in a big ball of fire all of the sudden. Stopped up cats can get glowing red hot and set vehicle on fire.

How much $ am I looking at?

If it was mine I would remove and inspect it myself. You can do this if yours is a bolt in version. Does your state do emissions testing or inspections? If no then a ten dollar splice pipe put in the place of the cat and you are back on the road. If we had the actual code number we could possible give you some other things to look at too.

And before anyone jumps on me about suggesting a splice pipe. Only use the splice pipe till you can afford to have a proper cat installed.

But if yours not a bolt in post the code number on here before you cut it out so we can double check what you were told about it being the cat. Would hate for you to cut a perfectly good cat out from under your vehicle.

Yes its welded in right where the two sides meet from the exhaust manifold

That sucks. Do you have an auto zone close by? If so drive there and have the codes read again. They will do this for free. Post Codes on here to give us clues as to what might be wrong. If can't drive it they will loan you a code reader for a deposit(you will get money back when you return it. ) Also look at cat after vehicle warms up. Is it glowing red?

You can get the codes with the ignition key trick, turn the key fast 3 times from off to on leaving it on on and the codes will appear in the dash where the odo is.

I did the ignition trick and got a P 0420 and a P 1296. Any ideas?

http://www.wjjeeps.com/faultcodes.htm

Mine did that and I replaced the relays in the fuse box under the hood. There is a relay that tells the vehicle it has rolled over, sometimes it burns closed. Try replacing the black box relays first, they are cheap to do. My durango purrs like a kitten now. Just can't get the damn thing out of bulldog, lever broke when a friend drove it. IDIOT. He shifted it at high speed.