I recently replaced the pre-cat on my daughters 02 nissan altima due to early signs of engine damage from the engine ingesting pieces of the ceramic pre-cat during negative exhaust conditions. I raise this issue because looking at my 01 RX . I see similar proximity of the pre-cat and was curious if any members had unexplained engine failure. This was a common problem and resulted in pre-cats being moved further downstream.

 

No issues with the RX, but that is a known issue on Altima's.