hi,i own(and love) a 92 mercedes 190e 2.0iauto,the thing is the cooling fan refuses to cut in,causing the engine to run hot.i replaced the cooling fan sensor in the cylinder head to no avail,yet when i joined the two wires that run to the sensor together the fan runs constantly.does any one have any ideas?cos im miffed.also the engine runs lumpy(misfires,revs its self up)whether its hot or cold.ive heard from a fellow 190 owner it could be the emitions sensor,could this be right??? any info,advise,would be gratefully received.thanks rick 1.