In Reply to: Just bought a 1997 740i posted by Ed Mose on March 13, 2000 at 17:56:10:
If the 7 uses the same catalytic converters as the 5, there was a manufacturing defect in the converters used on at least some of the 1997 cars. Apparently the guts come lose from the case. I also had to replace both on my 1997 540. This was an "infant mortality" issue.