The check engine light came on today. i was reading about how it could be the gas cap. I pulled the gas cap off and it actually blew out some gas. Any ideas? Its a 91 300sl

I drive a 94 sl320, when I fuel up after driving a few miles I experience a pressure build up when removing the cap. I don't know if this is normal, but the car runs great and does not have any lights on. Good luck.

It can be a series of malfunctions that MB wants you to seek solutions. A code can be read with the proper scanner from the OBD plug. Our older models have a mixed system, that may be beyond the shade tree mechanic!
My 600 gets a CEL from the MAS, the car runs great but a small particle was discovered by the air sensor! I have the car checked annually, but the code has been the same for the last decade.

Engine light on, means engine thing to be care of,,

M

Have it scanned, there are DOZENS of things that can set a check engine light on. Don't assume it is anything.

even it could be a screw !!

good luck

M