front o2
As for passing emission testing, you may want to pose this question in the regional forums (or talk to a testing location near you). The requirements differ from state to state (sometimes within a state). If you delete the rear O2s it will show as an incomplete test on an OBD II scanner for the catalyst system. I believe the strictest emissions tests (California for example) allow for one incomplete for 2001 and newer cars, so you should be ok. Check locally to be sure.



