what would cause high idle rpm test
my 300e mercedes-benz 1992 failthe emission due to adle reading 262 allowed 220 on 1992 Mercedes-Benz 300E
i assume that your talking hardra carbons. if so it indicates a slight misfire or poss bad catt. are the other readings good?
The other reading is good hc ppm 97 co51idle rpm 262 allowed 220 co+c02 13.7 how wouldyou know that your catt bad
your co2 is slightly low should be 14.2 which means your mixture is off a little have catt temp ck w/ digital therm. see how hot it is in the frt and then ck the rear of catt. if not sure ck with a muffler shop