I took it a part and discovered that the two part looked different..on close inspection: the original part was a 35 not a 36...installed it anyway and still has a rough idle..taking it to an independent tomorrow..they seem to think that one of the coils is bad..which one..they don't know..is there any difference between the 000 159 35 42 part number and the 36? Anyhow, this is getting beyond me now..thanks for all the help.....