I am going to replace the O2 sensors and c atalitic converters on my 535xi and looking at some tips from the community. Im installing the oem down pipes not any aftermarket dp.
how feasible is doing the job without a lift?

 

The job is very feasible without a lift. Just be prepared for cramping and cursing. There is very little space to work in and any set of DPs (including OEM) are a tight fit. Fitment of the DPs is the only real challenge to the job though. I consider myself between novice and intermediate in automechanic knowledge and skill, and I installed my AR DPs with the car on jack stands.

 

This thread helped me get through the install:

https://5series.net/forums/e61-touri...talled-146263/

hatterasman provides nearly all the info that you may need, and I I added a few notes to the end about my experience.