My 2003 Ford F-150 check engine light stating oxygen bank 2 sensor.

It's a 4.2 or 5.6. I'm not really for sure.

well,if you open the hood,it tells you right on top of the engine cover!4.2L,4.6L,5.4L THERE IS NO 5.6L! 4.2L is a 6 cyl. 4.6L and 5.4L are 8 cyl.!

I did read it from underneath the hood of my truck and I get two readings. One says 4.6/5.4L and the other says 4.2L. Sorry if I didn't get the engine sizes right for you.

you are looking at the belt routing diagram on the label on the radiator shroud!LOOK ON BLACK COVER ON TOP OF THE ENGINE.

Oh ok. Learn something new thank you...lol! it's a 5.4L

check the vacuum hoses again.there is one that gives a lot of trouble,it goes to the pcv valve and to the back of the intake manifold at the top,and one other place.check it real good.it splits and rots.big rubber boot at back of engine in intake,also at the pcv valve.it will collapse and mash flat there.it may be covered in foam insulation,may have to cut it back a couple inches to see it.post findings.

Ok great and thank you so VERY much for your advice. Blessings Andrea. :)

your welcome, post findings.