2000 7.3 Ford excursion hard start

[powerstroke977.3]

Recently I changed the hpop on my excursion because i had a bad oil leak and that's what a mechanic said the problem was. After i replaced it i tired to start it and it took twice to get it to start but i did not think much of it. So i take it for a test drive and come back a let it sit for a min and then try to restart and again it took two times. Some times it will start up on its first try but most times it takes two to get it running. So i was wonder what it could be i looked at all the connections and the look fine i plugged in my scanner and got p0742 exhaust senser. And as fair as i can tell there is still an oil leak but it may just be left over oil.