Hello everyone.....My neighbors mb/bmw mechanic made a service call
nextstore and told me I have to have the O2 Sensor and a catalytic
converter hooked up so the car will run without a computetr glitch.  After
talking to him I looked at the metal end of the 02 sensor and learned that
the metal was a beat up and bend a little.  I saw that there is a rubber
insulation piece that guides the wires through inside somewhere.  MY
QUESTION- Is there a way to get to the other end from the inside of the
car?  Is it a hard job? Is 300 dollars a good price for an aftermarket
CAT?  Whats the difference between one CAT and an aftermarket cat? Thank
you all- Charlie- Monmouth County NJ