Vibrations while acceleration

Took my Tacoma to the dealer because the check engine light came on. They said that it was the O2 sensor or the catalectic converter. Replaced both, and I still have the vibration. I have a automatic transmission and notice the vibration on acceleration during low rpm and shifting between 45 to 50 mph. Any ideas.

 

Sounds like the "mystery" problem that Toyota can't figure out.

 

My 2011 does it consistently at 1000 to 1200 RPMs. I'm taking it in Friday but don't really expect much of a resolution. I haven't been real impressed with the service so far. This is my first new Toyota. I guess I had unrealistic expectations.

 

dhk, thanks. Put the truck on a life at a friends shop, carrier bearing was loose. He said that it takes a while for the u-joints to go bad, because of the grease fitting. Thanks again