Really good read I thought I'd share with you guys outlining the Bosch LSU 4.2 and 4.9 sensors. It explains their common failure causes and mitigation strategies. This is really intended for people performing aftermarket installs but can be applied to our situation(s) as well.
http://www.nzefi.com/bosch-lsu-wide...l-often-aftermarket-performance-applications/
http://www.nzefi.com/bosch-lsu-wide...l-often-aftermarket-performance-applications/