No CEL...No fault code..??? - PeachParts Mercedes-Benz Forum

OTTOBUN · #1 11-20-2006, 02:20 PM

300E 1990, per my tech shop:

My oxygen sensor is inop and catalytic conv is now toast, but I have no CE light (never have) and they're not getting any fault codes whatsoever...

How can this be?

OTTOBUN · #2 12-13-2006, 08:30 PM

To update my own post...Merry christmas to all, and to my old 300e!

Took the old girl to an old trusted tech, put in a new Ox sensor...and voila! Passed Ontario e-test with flying colors!
My HC went from twice allowable to perfect. No new Cat needed!

He thought it was weird I got no CEL but shrugged.

Here's a word to the wise...we both looked at the exhaust fumes this AM, and he was sure the engine was burning oil...he thought A LOT of oil. Time for valves and seals, he prepared me for.

But really it was lots of unburnt fuel...looked like coolant smoke but was just gas. I read that unburnt gas would be black, but this time it was just rich and white.

Im very happy!

Merry Christmas / Happy Hannukah / Blissful Kwanzaa and seasons greetings to all other fine folks on this fantastic site!!

manny · #3 12-13-2006, 08:49 PM

Congratulations.
Btw., if you were burning a LOT of oil, your HC would be through the roof ( probably somewhere in the 1000's ).

OTTOBUN · #4 12-13-2006, 09:12 PM

Quote:

Originally Posted by manny

Congratulations.
Btw., if you were burning a LOT of oil, your HC would be through the roof ( probably somewhere in the 1000's ).

Thanks Manny..

Ill tell you a funny story...when it got tested in Sept. it failed the high (2500 rpm) test HC with a result of 94ppm vs limit 50ppm. This was from a real Drive Clean computer My new paper says 35ppm vs. limit 200: PASS at that high speed. All my old test result papers say 200 PPM at both idle and 2500rpm.

Was there ever a limit of 50 PMM in Ontario on my car?. Even my OLD results from '94, '92 etc say limit 200 pm at both idle and 2500rpm?

Either way, I needed a new O2 sensor. and it did it's job cept tell me with a CEL..