Guys...

Well I can confirm the '95 E420 O2 sensor location was designed by satan himself. Topside of the exhaust - vicinity of the "y" connection - pre-converter (naturally). The threaded bung is actually in a small recess - making it IMPOSSIBLE to get a wrench on. So you're forced to use a socket. Because of the wire - crow's foot socket! THE TOOL POPULATION GROWS AGAIN! ha ha!

Can also confirm - just one sensor (pre-cat) on this model.

Unfortunately...can't yet address whether the new sensor fixed the code issue - since soon as I got this done - I had to put brakes & shocks on the Landcruiser. (Snapped 2 caliper bolts - had to drill and tap threads in the steering knuckle - talk about PITA!)

Just wanted to say thanks for the help and advice - I'll chime in with "worthwhile" commentary on the diagnosis and fix when I get the car off the blocks tonight.

Jim

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Syntax26

1995 MB E420 (lowered)
1989 MB 300SE (sold to brother)
1975 MB 280 (sold)
One damn fine jacked-up golf cart