Hi MB gang. Well, today for the first time, my CEL came on a couple of times and went off. First of all, the car is a 1988 300SEL with 154K miles.

First time was when I first left this afternoon, I let the car warm up for a couple of minutes- then pulled away. I got about .4 of a mile down the road to the main road and noticed the red check engine light illuminated.... thinking "this is just great", about .5 down on down the road, it went off and did not come back on during that trip. I went to the mall and was inside for a few minutes, came out, started the car and again - got about .2 down the road and the CEL came on and was on again for 1/2 a mile and went off and did not come back on.

Now, this is my 4th Mercedes, but the first time I ever had a CEL light issue, so not sure what to do. I am assuming that the light needs to come on and stay on before the testing would show anything? Also, where is the "diagnostics plug" on this car? Lastly, is this a car that I can simply take somewhere like autozone to get it checked, or is this going to be a MB-tech or dealer testing only? The car is running good and no different. I have read its common, but the only thing is that I have a splutter at idle. I am assuming it needs new plugs or ? I have read this is a common problem with these.

Sorry for being so clueless on the MB CEL's, but as mentioned, I am not familiar with them. Now if it was a CEL on one of our old 80s-90s GM cars, I could tell you in a second. I do not think there is a 1980s-1990s GM car on the road on which the check engine light is not illuminated. Our 98' Oldsmobile is one of them, despite testing and replacing parts they said it needed.

Thanks!