Recently had a "a service" done on my 2006 S430.

A few days later the check engine light came on.

no loss of power or lack of performance.

I unscrewed the gas cap and cleaned the surrounding areas.
Drove for two days with out incident.
Third day came back on. this time I gave it a really good cleaning, and once again the light went off.
Should I have it tested for possible codes or just buy a new gas cap if the light come on again?

thanks

 

I kind of doubt its your gas cap turning the light on.