Hello.
1991 Mercedes 300SE, 3.2 I6 with 195k miles on the clock.
I'm having trouble with Merc's emissions: CO is 0.45% (limit(0.30%) and HC around 200 (limit 100).
Basic parts have been changed ie. plugs, wires, ECM temperature sensor, O2 sensor, catalytic converters, distributor cap and...