For the past couple weeks I have had a P0300 (Multiple Cylinder Misfire) Check Engine error code. I have reset it and after a couple days it seems to come back on. I took the vehicle to the dealer to get an oil change done last week and it has not come on since.

Couple questions/comments:

Is this something major that I should get checked out?

I have not noticed a decrease in power from the vehicle when this error is triggered.

Could this be related to ULSD?

I have not driven the car much since the switchover but recently I have been driving the car fairly frequently and I have filled up maybe 10 times since ULSD came out.

I am hoping its not something major but if it is I would like to know so I do not cause further damage to the vehicle. After the oil change the light has not come on for the past week or so....Thanks

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1999 E300
1995 E300
1994 SL320
1988 560SL
1987 300TD
1982 300D
1955 300SL