Mercedes Benz C200 Kom Sport 2.0 1998 - Failed emissions #
Posted by Paul Cuncliffe on December 8, 2010, 8:21 pm
Year of Manufacture *: 1998 Engine Size and Code *: 2000 ( Optional ) Scanner Used: KTS
FAILED EMISSIONS. HIGH CO 3.50 LOW LAMBDA 0.92. CO AND LAMBDA GET BETTER ON TICK OVER . SCOPED OXYGEN SENSOR HIGH ON O.6 SLIGHT SWITCHING CREATE AIR LEAK AND DROPS TO 0.1 THEN GOES TOO 0.6 AGAIN. HC HIGH 200 .CAR HAS HAD NEW MANIFOLD AND OXYGEN SENSOR FITTED BY ANOTHER GARAGE. MASS AIR FLOW 1.0 VOLT TOO 4.00 ON SNAP THROTTLE. ALSO LOOKS LIKE CHEAP CAT FITTED BEFORE. CAR HAS DONE 100,000 MILES PLEASE HELP GOING MAD.
Firstly don't worry about the cheap cat at this point, These readings are to far out to be a problem with the Cat alone. The lambda reading should pass/meet MOT limits without a cat, so get that right first.
I would say that 0.6 v is low for engine that is that rich. what does live data show ? is it a good quality sensor fitted.
What is live data showing on MAF, CTS, Lambda etc ?? Any fuel trim info ?
Other points to eliminate are fuel pressure and pre cat air leaks.
Basic checks, compressions, manifold vacuum, inlet leaks, plugs, oil quality, air filter etc should be carried out.
on December 8, 2010, 9:27 pm, in reply to "