I have used WD-40 many times as a starting fluid, the aerosol can type that is....
On my old Triumph TR-3 with side draft carbs....
Always have a can ready if Im going to help some one whos stranded or needs car help.
I heard It has Naptha in it (Naphalm Bomb) works great on old engines and helps in first crank but I dont know if its good for sensors on newer cars?
I installed a oil bath type filter (like K@N) on mine once, and I put too much oil on the new filter I think? Well it did the same stuff yours is doing for a day or so till all the oil was gone then no problems....
MAF? dirty? I agree with Spensley.