I am at my wits end with my car. I know very little about car repair and maintenance and that alone makes me enraged.
So my car is very old and has not been taken care of before I owned it. It did misfire at idle speed before but very rarely, now it seems that ever since I put more oil in the misfires happen way more frequently. I put in a synthetic 10w 30 oil and the engine is way more quiet now and the gas mileage is slightly better…but ever since I put it in the misfires are frequent. I do not know if it is a vacuum leak or a spark plug problem, or if it has something to do with the oil