Hello,

what a sad day ! I took my 1991 190E 2.6 to the state inspection today for the first time I own it and failed the emission test.

It failed for HC and NOx:

HC ppm 189 Hi-speed (should <120) 188 lo-speed (should <124)
NOx 1685 Hi speed (should <848), 1894 lo-speed (should <937)
CO % 0.42 / 0.43
CO2 % 14.3 / 14.3
O2% 0.6 / 0.6
Dilution % 14.7 / 14.7

One mistake I already realized was that I had low octane fuel in the tank.

Any recommendation what I need to look for ? Is the catalytic converter damaged ? Is the engine burning oil or coolant water ?

Any help is welcome !

Thanks !