Our 2000 C280 had the B service performed by Ewing ******** in Plano, Texas 4 months ago @ 35,190 miles. The Check Engine light came on about three weeks ago @ about 37,000 miles and we took it back to Ewing. They checked it out and said the only thing they could find was a loose gas cap. The mechanic said to fill the tank again and drive it for a while and the light should go out - if not we were to take it back to them. After two fill ups the light is still on. Any ideas? Also, can anyone recommend a good shop in/around Collin County, Texas? Thanks in advance!

use the search here to learn about CEL

you have an Autozone around you to have them read the OBDII codes for free, then you can bring the codes abck here and find out what they mean

Will do - thanks Ethan!

Did they read the codes? It does not sound like it. Sounds like they were in a rush to get you out of the driveway. You'll have to have the codes read, and preferably have someone with SDS (Star Diagnostic System) also read the adaptation values. Those two things will bring you much closer to a proper diagnosis.

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John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif

Autozone read the code for me @ n/c - thanks for the suggestion! The code is P0170. FYI, the car seems to be running fine, and passed the Texas emission test today with the CEL still on.

Well, you're off to a good start. That is typically a fuel trim malfunction, and most of the time that is either a failing fuel pressure regulator (cheap) or the more common Air Mass Meter (expensive). By checking the fuel trim adaptation values, you'll be steered in the right direction. High values should ahve you swapping in a new AMM and rechecking. Low values mean try the pressure regulator.

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John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif

I can't believe you can pass smog with the check engine light on. California will not let that go. CEL on is immediate failure......do not pass go.