Mercedes-Benz M-Class Maintenance Booklet page 15

d) The operation of the emission con-
trol system must not be altered in
any way. Alterations are not permissi-
ble by law. In addition, alterations may
result in damage to the catalysts, in-
creased fuel consumption, and im-
paired engine running conditions.
e) Irregular engine running conditions
should be corrected immediately
by an authorized Mercedes-Benz
Light Truck Center. Such irregular
running conditions can influence the
proper function of the emission con-
trol system.
Maintenance Booklet
Emission System Maintenance
If the "CHECK ENGINE" indicator lamp in
the instrument cluster illuminates when
the engine is running, it indicates a possi-
ble malfunction of the engine manage-
ment system or emission control system.
We recommend that you have the mal-
function checked as soon as possible.
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