'97 S500, 87K miles.

got CE light the other day. OBDII reader gave this code. EASE library says..'main cataylist efficiency Bank 2 below threshold'...

anybody have a more precise indication of the problem?

p/o had cat welded in place, i suspect may be non-stock. is this an indication that the cat is going bad?

TIA

That code means that the rear O2 sensor is seeing almost as much oxygen as the front O2 sensor, bad catalyst!! Drivers side.

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thanks. was afraid of that.