computer keeps reading O2 sensor when engine light comes on....engine surges/revs with increased speed. 2 sensors have been replaced.....why oh why???

This vehicle has been in for service about 20 (15 for the surging) days during the first 12 months of ownership. The Chrysler Rep. claims that it's normal on this type of vehicle (Nitro, Liberty, Dakota, and Mini Vans) I think that if Chrysler has knowledge of the problem they should go back to the drawing board and get it corrected. When I was shopping for the vehicle I did not find this problem listed in any printed information.