I have an 2003 Rodeo S (V6). Any recomendation on which 02 sensors, and part numbers, to get? Any tricks or things to watch out for when replacing. I was going to do all four (I think there are four) and get it over with. Thanks in advance for any help.

there should be four , two before the cats and two after

Why are you replacing? Getting codes?

I'm still on the originals (all 4) on a 2001 Passport with 130K miles. No codes; no problems.

Just order them based on the vehicle series/motor. Be sure & get 4-wire/heated. An O2 sensor is pretty generic, there's a wide range of units that will work. They'll cost you between about $35-$65 depending on whether you get Denso OEM's or other aftermarket. Careful, some (cheaper ones) don't come with the connector. You have to splice them in from the originals. Not a big deal, a little solder & wire shrink-wrap does it.

Nothing complicated about replacement. Just be sure & use plenty of anti-sieze on threads when you install. Else, you'll never get em out again. They usually come from manufacturer with a dab of anti-sieze, but it's not enough IMHO. I add more.