I was recently following my S320 in traffic (wife was driving...) and noticed a pesty foul exhaust smell.
Now I have had some problems with a surging idle and some ruff running at the highway. And a Oxygen sensor warning (check engine light)
Is it possible my Catalyst is bad or clogged?
How would I check?
regards,
Sab.

__________________
regards,
Sab.
'07 ML320 CDI (398 ft lbs / 1400 RPM)
'02CL 500
'91 928 GT Supercharged