Take it to a place like Advance Auto or AutoZone and have them read and delete the old codes. Might be something simple on the way out. At least you will know and the price is free.
> IIRC it takes somewhere on the order of 50(?) starts to clear the
> failure code, so there is a good chance that the fail code is in fact > still stored.
>
> I had an SES on my 98SL2 recently that came on for a day or so and then
> went out. I took it in to the dealership anyways, just to be sure -
> they were able to retrieve the code. I don't remember exactly what the
> code was, something about the resistance of the plug wires.
>
> Not sure about the newer models, but if I cycle my cruise control on and
> off several times (7?), it instructs the computer to take a snap-shot of
> the current input readings/parameters - this is supposed to be useful
> for intermittent problems where the SES doesn't come on, and you can't
> replicate the problem at the shop.
>
> -rj
> 98SL2