I own a c240 2001 and recently it just has been turning off in the middle of the street while in traffic or stopped at a red light. I changed all the filters and put in fuel injection , nothing seems to work. It had "Check Coolant Level " on for sometime, but the coolant level is fine. Also we took it to AUTOZONE and the machine pulled up 2 problems, PO 175 (O2 sensor) and PO 335 (crank sensor), what are these and what do they mean. Mercedes is going to charge me and arm and a leg to diagnos it let along the labor to fix it and parts. So, I was hoping that someone would know what these PO's mean and help me out!!! thanks!!

Desperate~